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DX-7 battery replacement (with holder?)

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  • Hal
    I m servicing my DX-7 (original model) and also need to replace the battery. I m not very happy with soldered-in batteries so the idea was to replace it with a
    Message 1 of 21 , May 6, 2017
      I'm servicing my DX-7 (original model) and also need to replace the
      battery. I'm not very happy with soldered-in batteries so the idea was
      to replace it with a CR-2032 battery holder so I never need to de-solder
      it again.

      But I see the battery area is quite cramped, and the OSH-park battery
      saver PCB (https://oshpark.com/shared_projects/xdfK07Ms) won't fit. With
      other synths I've soldered a wire end (from a resistor etc.) to one of
      its terminals in order to extend the pin-pin distance (the soldered-in
      batteries have a different distance than the holders) but I don't like
      to do this as it can get loose (or partly loose) when soldering the
      other end to the synth PCB.

      Any good suggestions if I want to use a battery holder in the DX-7?


      Hal
    • Takis
      The easiest method is to cut the leads of the old battery solder two wires (mind the polarity) directly on them,twist the wires in a tight braid and then
      Message 2 of 21 , May 6, 2017

        The easiest method is to cut the leads of the old battery solder two wires (mind the polarity) directly on them,twist the wires in a tight braid and then solder a battery holder on to them.

        Use heatshrink on the battery holder terminals to insulate the leads.

        Bend the battery holder leads as flat as possible and use some double sided tape to mount the battery holder somewhere less crowded.

        You could heatshrink the entire battery holder and just mount it anywhere.The new CR2032 will last at least 5 years so you won't be messing with it anytime soon.

        I prefer removing the board and properly install a battery holder but if that makes you uncomfortable the above method is fast and safe.


        On 5/6/2017 12:40 PM, Hal my_list_address@... [yamahablackboxes] wrote:
         

        I'm servicing my DX-7 (original model) and also need to replace the
        battery. I'm not very happy with soldered-in batteries so the idea was
        to replace it with a CR-2032 battery holder so I never need to de-solder
        it again.

        But I see the battery area is quite cramped, and the OSH-park battery
        saver PCB (https://oshpark.com/shared_projects/xdfK07Ms) won't fit. With
        other synths I've soldered a wire end (from a resistor etc.) to one of
        its terminals in order to extend the pin-pin distance (the soldered-in
        batteries have a different distance than the holders) but I don't like
        to do this as it can get loose (or partly loose) when soldering the
        other end to the synth PCB.

        Any good suggestions if I want to use a battery holder in the DX-7?

        Hal


      • Grant B
        Two things ... The resistor you are talking about is a current limiting resistor. So it saves both the backlight LED(s) and the power supply from over
        Message 3 of 21 , May 6, 2017
          Two things ...

          The resistor you are talking about is a current limiting resistor. So it
          saves both the backlight LED(s) and the power supply from over
          consumption. Keep the value as high as possible while also enjoying the LCD.

          I would never recommend heating (to shrink the heatshrink) a lithium
          battery. Even in such a small form factor, the lithium CR2032 size
          batteries can do a lot of damage. Google that for videos.
        • Hal
          ... Removing the DX-7 board is fine, and I prefer to do it properly to start with. You gave me a good idea when you mentioned twisting the wires though -I ll
          Message 4 of 21 , May 6, 2017
            On 06/05/17 11:48, Takis belzrebuth@... [yamahablackboxes] wrote:
            > The easiest method is to cut the leads of the old battery solder two
            > wires (mind the polarity) directly on them,twist the wires in a tight
            > braid and then solder a battery holder on to them.
            >
            > Use heatshrink on the battery holder terminals to insulate the leads.
            >
            > Bend the battery holder leads as flat as possible and use some double
            > sided tape to mount the battery holder somewhere less crowded.
            >
            > You could heatshrink the entire battery holder and just mount it
            > anywhere.The new CR2032 will last at least 5 years so you won't be
            > messing with it anytime soon.
            >
            > I prefer removing the board and properly install a battery holder but if
            > that makes you uncomfortable the above method is fast and safe.

            Removing the DX-7 board is fine, and I prefer to do it properly to start
            with.
            You gave me a good idea when you mentioned twisting the wires though
            -I'll do that with a connecting wire or end of a resistor so that it
            also has an additional fastening to the solder. And if I solder the
            board end quickly I should probably not melt the solder at the other end.

            The Osh-park battery adapter PCB I mentioned in my previous message is a
            great idea (it allows a standard battery holder to be connected to PCBs
            with several different pin spacings meant for soldered-in batteries, but
            alas it won't fit the DX-7 (even though I read that its main use was for
            the DX-7. I think I saw a picture of a DX-7 II board somewhere which had
            a lot more room around the battery).

            In my other synths I also fastened the battery holder on to the PCB by
            using hot glue, but read somewhere that it might be harmful to the
            circuitry/components -any truth to that? I did make a huge mistake of
            using silicone (the type you use in bathrooms) for some gear, only to
            hear that it contains some sort of acidic material which will damage
            electronic components and PCBs, so I quickly removed it.


            Hal
          • Takis
            Heatshrink tubing is essential. Heating obviously is done before installing the battery!
            Message 5 of 21 , May 6, 2017

              Heatshrink tubing is essential.

              Heating obviously is done before installing the battery!


              On 5/6/2017 5:58 PM, Grant B grantbt@... [yamahablackboxes] wrote:
               

              Two things ...

              The resistor you are talking about is a current limiting resistor. So it
              saves both the backlight LED(s) and the power supply from over
              consumption. Keep the value as high as possible while also enjoying the LCD.

              I would never recommend heating (to shrink the heatshrink) a lithium
              battery. Even in such a small form factor, the lithium CR2032 size
              batteries can do a lot of damage. Google that for videos.


            • Takis
              Hot glue is not pretty but fine for pcb.Won t do any harm.Quality double sided tape is tidier though..
              Message 6 of 21 , May 6, 2017

                Hot glue is not pretty but fine for pcb.Won't do any harm.Quality double sided tape is tidier though..


                On 5/6/2017 6:03 PM, Hal my_list_address@... [yamahablackboxes] wrote:
                 

                On 06/05/17 11:48, Takis belzrebuth@... [yamahablackboxes] wrote:
                > The easiest method is to cut the leads of the old battery solder two
                > wires (mind the polarity) directly on them,twist the wires in a tight
                > braid and then solder a battery holder on to them.
                >
                > Use heatshrink on the battery holder terminals to insulate the leads.
                >
                > Bend the battery holder leads as flat as possible and use some double
                > sided tape to mount the battery holder somewhere less crowded.
                >
                > You could heatshrink the entire battery holder and just mount it
                > anywhere.The new CR2032 will last at least 5 years so you won't be
                > messing with it anytime soon.
                >
                > I prefer removing the board and properly install a battery holder but if
                > that makes you uncomfortable the above method is fast and safe.

                Removing the DX-7 board is fine, and I prefer to do it properly to start
                with.
                You gave me a good idea when you mentioned twisting the wires though
                -I'll do that with a connecting wire or end of a resistor so that it
                also has an additional fastening to the solder. And if I solder the
                board end quickly I should probably not melt the solder at the other end.

                The Osh-park battery adapter PCB I mentioned in my previous message is a
                great idea (it allows a standard battery holder to be connected to PCBs
                with several different pin spacings meant for soldered-in batteries, but
                alas it won't fit the DX-7 (even though I read that its main use was for
                the DX-7. I think I saw a picture of a DX-7 II board somewhere which had
                a lot more room around the battery).

                In my other synths I also fastened the battery holder on to the PCB by
                using hot glue, but read somewhere that it might be harmful to the
                circuitry/components -any truth to that? I did make a huge mistake of
                using silicone (the type you use in bathrooms) for some gear, only to
                hear that it contains some sort of acidic material which will damage
                electronic components and PCBs, so I quickly removed it.

                Hal


              • Daniel Forró
                1. It is possible to buy the battery with solder pins with exact width for DX7. 2. If not, there s a possibility to make new hole(s) in PCB for different size.
                Message 7 of 21 , May 6, 2017
                  1. It is possible to buy the battery with solder pins with exact width
                  for DX7.

                  2. If not, there's a possibility to make new hole(s) in PCB for
                  different size. If I remember well the soldering pad is enough big, at
                  least for one pin...

                  3. My general opinion about using the holders is well known - I don't
                  see any reason for it. It has sense for machines where we change
                  battery every six months or once a year. Why to put battery holder
                  into the instrument where the battery can work 5, 10 or even more
                  years? In some of my instruments the original battery has been working
                  for 25 years. So it's enough to replace it with the new one and leave
                  the next change after another 25 years to somebody who will inherit
                  the instrument after my funeral :-) There's also possible that
                  replaced battery will survive not only me, but the other circuitry in
                  the instrument.

                  Daniel Forro


                  On May 7, 2017, at 12:03 AM, Hal my_list_address@...
                  [yamahablackboxes] wrote:

                  > On 06/05/17 11:48, Takis belzrebuth@... [yamahablackboxes]
                  > wrote:
                  >> The easiest method is to cut the leads of the old battery solder two
                  >> wires (mind the polarity) directly on them,twist the wires in a tight
                  >> braid and then solder a battery holder on to them.
                  >>
                  >> Use heatshrink on the battery holder terminals to insulate the leads.
                  >>
                  >> Bend the battery holder leads as flat as possible and use some double
                  >> sided tape to mount the battery holder somewhere less crowded.
                  >>
                  >> You could heatshrink the entire battery holder and just mount it
                  >> anywhere.The new CR2032 will last at least 5 years so you won't be
                  >> messing with it anytime soon.
                  >>
                  >> I prefer removing the board and properly install a battery holder
                  >> but if
                  >> that makes you uncomfortable the above method is fast and safe.
                  >
                  > Removing the DX-7 board is fine, and I prefer to do it properly to
                  > start
                  > with.
                  > You gave me a good idea when you mentioned twisting the wires though
                  > -I'll do that with a connecting wire or end of a resistor so that it
                  > also has an additional fastening to the solder. And if I solder the
                  > board end quickly I should probably not melt the solder at the other
                  > end.
                  >
                  > The Osh-park battery adapter PCB I mentioned in my previous message
                  > is a
                  > great idea (it allows a standard battery holder to be connected to
                  > PCBs
                  > with several different pin spacings meant for soldered-in batteries,
                  > but
                  > alas it won't fit the DX-7 (even though I read that its main use was
                  > for
                  > the DX-7. I think I saw a picture of a DX-7 II board somewhere which
                  > had
                  > a lot more room around the battery).
                  >
                  > In my other synths I also fastened the battery holder on to the PCB by
                  > using hot glue, but read somewhere that it might be harmful to the
                  > circuitry/components -any truth to that? I did make a huge mistake of
                  > using silicone (the type you use in bathrooms) for some gear, only to
                  > hear that it contains some sort of acidic material which will damage
                  > electronic components and PCBs, so I quickly removed it.
                  >
                  >
                  > Hal
                  >
                  >
                  > ------------------------------------
                  > Posted by: Hal <my_list_address@...>
                  > ------------------------------------
                  >
                  >
                  > ------------------------------------
                  >
                  > Yahoo Groups Links
                  >
                  >
                  >
                • Takis
                  @grantbt@jps.net Oh,I was talking about individually insulating the holder contacts.Now I see what you mean about heatshrinking the whole battery. I agree that
                  Message 8 of 21 , May 6, 2017

                    @grantbt@...

                    Oh,I was talking about individually insulating the holder contacts.Now I see what you mean about heatshrinking the whole battery.

                    I agree that heating any sort of battery can end up badly but I've tried the method I've described above a few times with no issues.I've even soldered directly on battery contacts with no issues.(you have to use flux and sand them first)

                    You're right though; if you apply excessive heat and don't do it quick bad things could happen.


                    On 5/6/2017 5:58 PM, Grant B grantbt@... [yamahablackboxes] wrote:
                     

                    Two things ...

                    The resistor you are talking about is a current limiting resistor. So it
                    saves both the backlight LED(s) and the power supply from over
                    consumption. Keep the value as high as possible while also enjoying the LCD.

                    I would never recommend heating (to shrink the heatshrink) a lithium
                    battery. Even in such a small form factor, the lithium CR2032 size
                    batteries can do a lot of damage. Google that for videos.


                  • Daniel Forró
                    Even well done soldering directly on the battery can shorten its life... Daniel Forro On May 7, 2017, at 12:16 AM, Takis belzrebuth@yahoo.com
                    Message 9 of 21 , May 6, 2017
                      Even well done soldering directly on the battery can shorten its life... 

                      Daniel Forro


                      On May 7, 2017, at 12:16 AM, Takis belzrebuth@... [yamahablackboxes] wrote:

                      You're right though; if you apply excessive heat and don't do it quick bad things could happen.


                    • Grant B
                      Hi Daniel, I disagree with point #1. If they were available, people would sell them on eBay for the DX7. ;) I agree with point #3, especially for a musician
                      Message 10 of 21 , May 6, 2017
                        Hi Daniel,

                        I disagree with point #1. If they were available, people would sell them
                        on eBay for the DX7. ;)

                        I agree with point #3, especially for a musician who plays live and
                        moves his synth around. It was good enough for Yamaha ...

                        On 5/6/2017 8:15 AM, Daniel Forró danforcz@... [yamahablackboxes]
                        wrote:
                        >
                        >
                        > 1. It is possible to buy the battery with solder pins with exact width
                        > for DX7.
                        >
                        > 2. If not, there's a possibility to make new hole(s) in PCB for
                        > different size. If I remember well the soldering pad is enough big, at
                        > least for one pin...
                        >
                        > 3. My general opinion about using the holders is well known - I don't
                        > see any reason for it. It has sense for machines where we change
                        > battery every six months or once a year. Why to put battery holder
                        > into the instrument where the battery can work 5, 10 or even more
                        > years? In some of my instruments the original battery has been working
                        > for 25 years. So it's enough to replace it with the new one and leave
                        > the next change after another 25 years to somebody who will inherit
                        > the instrument after my funeral :-) There's also possible that
                        > replaced battery will survive not only me, but the other circuitry in
                        > the instrument.
                        >
                        > Daniel Forro
                      • Hal
                        ... Where? I ve searched but never found anything with the same pin spacing. ... Hmmm... I didn t think of that, but I will surely look into it when I
                        Message 11 of 21 , May 6, 2017
                          On 06/05/17 17:15, Daniel Forró danforcz@... [yamahablackboxes] wrote:
                          > 1. It is possible to buy the battery with solder pins with exact width
                          > for DX7.

                          Where?
                          I've searched but never found anything with the same pin spacing.



                          > 2. If not, there's a possibility to make new hole(s) in PCB for
                          > different size. If I remember well the soldering pad is enough big, at
                          > least for one pin...

                          Hmmm... I didn't think of that, but I will surely look into it when I
                          disassemble the main PCB.


                          > years? In some of my instruments the original battery has been working
                          > for 25 years. So it's enough to replace it with the new one and leave
                          > the next change after another 25 years to somebody who will inherit
                          > the instrument after my funeral :-) There's also possible that
                          > replaced battery will survive not only me, but the other circuitry in
                          > the instrument.

                          Correct me if I'm wrong, but are you saying the life of soldered-in coin
                          cells are greater than regular coin cell batteries?


                          Hal
                        • Daniel Forró
                          On May 7, 2017, at 12:31 AM, Hal my_list_address@yahoo.no ... I ve got bunch of them about 8 years ago in one shop in Tokyo Akihabara. Good offer has also
                          Message 12 of 21 , May 6, 2017
                            On May 7, 2017, at 12:31 AM, Hal my_list_address@...
                            [yamahablackboxes] wrote:

                            > On 06/05/17 17:15, Daniel Forró danforcz@...
                            > [yamahablackboxes] wrote:
                            >> 1. It is possible to buy the battery with solder pins with exact
                            >> width
                            >> for DX7.
                            >
                            > Where?
                            > I've searched but never found anything with the same pin spacing.

                            I've got bunch of them about 8 years ago in one shop in Tokyo Akihabara.

                            Good offer has also Renata:

                            http://www.renata.com/industrial-products/tabbed-coin-cells/

                            >
                            > Correct me if I'm wrong, but are you saying the life of soldered-in
                            > coin
                            > cells are greater than regular coin cell batteries?

                            I'm not sure if the battery life span has any connection to
                            soldering... but who knows - maybe they were made better because
                            replacement was not so easy as the battery in the holder.

                            Or maybe generally the batteries produced 25 years had better quality
                            than recent cheap Chinese sh!&. Everything was better in our younger
                            days, wasn't it :-)

                            Daniel Forro
                          • Hal
                            ... Sorry, I read your reply a bit too quickly and was thinking of battery *HOLDERS* (which I still haven t found with the same pin spacing as the soldered-in
                            Message 13 of 21 , May 6, 2017
                              On 06/05/17 18:18, Daniel Forró danforcz@... [yamahablackboxes] wrote:
                              > On May 7, 2017, at 12:31 AM, Hal my_list_address@...
                              > [yamahablackboxes] wrote:
                              >
                              > > On 06/05/17 17:15, Daniel Forró danforcz@...
                              > > [yamahablackboxes] wrote:
                              > >> 1. It is possible to buy the battery with solder pins with exact
                              > >> width
                              > >> for DX7.
                              > >
                              > > Where?
                              > > I've searched but never found anything with the same pin spacing.
                              >
                              > I've got bunch of them about 8 years ago in one shop in Tokyo Akihabara.
                              >
                              > Good offer has also Renata:
                              >
                              > http://www.renata.com/industrial-products/tabbed-coin-cells/

                              Sorry, I read your reply a bit too quickly and was thinking of battery
                              *HOLDERS* (which I still haven't found with the same pin spacing as the
                              soldered-in batteries.
                              I've found soldered-in coin cell batteries with the same dimensions of
                              other synths many places though. I suppose there's a standard, but
                              obviously not the same as with the battery holders for some (irritating)
                              reason.


                              > > Correct me if I'm wrong, but are you saying the life of soldered-in
                              > > coin
                              > > cells are greater than regular coin cell batteries?
                              >
                              > I'm not sure if the battery life span has any connection to
                              > soldering... but who knows - maybe they were made better because
                              > replacement was not so easy as the battery in the holder.
                              >
                              > Or maybe generally the batteries produced 25 years had better quality
                              > than recent cheap Chinese sh!&. Everything was better in our younger
                              > days, wasn't it :-)

                              Too true ;-)
                              I personally prefer to not desolder a PCB more times than I ever need
                              to. It's a hassle to remove the board and there's always a danger of
                              damaging or weakening the traces.
                              There's also a danger of having batteries like that explode when you
                              heat them up (or so I've heard) which is why you should always cut them
                              off with pliers first, then desolder the mounting pins. Soldering the
                              new ones is of course a risk which can't be avoided...

                              As for batteries, I always try to buy quality brands like Varta. I'm not
                              sure they're made in Germany, but I assume they're of much higher
                              quality than cheapo eBay Chinese no-name brand batteries.


                              Hal
                            • Hal
                              By the way... are there any good instructions anywhere on how to disassemble the DX-7 (at least so far as to remove the circuit board for changing the
                              Message 14 of 21 , May 6, 2017
                                By the way... are there any good instructions anywhere on how to
                                disassemble the DX-7 (at least so far as to remove the circuit board for
                                changing the battery)?

                                I found this page (http://alexannesty.com/dx7s-battery-replacement.php),
                                but it appears to be for a DX-7s. Do I really have to remove the whole
                                keyboard assembly on the original DX-7 as well just to remove the main
                                board?

                                Hal
                              • Takis
                                Check this video . https://www.youtube.com/watch?v=vzYu63wJaoM There are plenty other YT videos about how to replace the battery on a DX7
                                Message 15 of 21 , May 6, 2017

                                  Check this video .

                                  https://www.youtube.com/watch?v=vzYu63wJaoM

                                  There are plenty other YT videos about how to replace the battery on a DX7

                                  On 5/6/2017 11:01 PM, Hal my_list_address@... [yamahablackboxes] wrote:
                                   

                                  By the way... are there any good instructions anywhere on how to
                                  disassemble the DX-7 (at least so far as to remove the circuit board for
                                  changing the battery)?

                                  I found this page (http://alexannesty.com/dx7s-battery-replacement.php),
                                  but it appears to be for a DX-7s. Do I really have to remove the whole
                                  keyboard assembly on the original DX-7 as well just to remove the main
                                  board?

                                  Hal


                                • Takis
                                  Great tip on that video about the pcb connectors.I remember putting different color dots on each one before realising each one is unique..!
                                  Message 16 of 21 , May 6, 2017

                                    Great tip on that video about the pcb connectors.I remember putting different color dots on each one before realising each one is unique..!


                                    On 5/6/2017 11:59 PM, Takis belzrebuth@... [yamahablackboxes] wrote:
                                     

                                    Check this video .

                                    https://www.youtube.com/watch?v=vzYu63wJaoM

                                    There are plenty other YT videos about how to replace the battery on a DX7

                                    On 5/6/2017 11:01 PM, Hal my_list_address@... [yamahablackboxes] wrote:
                                     

                                    By the way... are there any good instructions anywhere on how to
                                    disassemble the DX-7 (at least so far as to remove the circuit board for
                                    changing the battery)?

                                    I found this page (http://alexannesty.com/dx7s-battery-replacement.php),
                                    but it appears to be for a DX-7s. Do I really have to remove the whole
                                    keyboard assembly on the original DX-7 as well just to remove the main
                                    board?

                                    Hal



                                • Daniel Forró
                                  I use tape stripes over the cable near the connector and write down the connector number. Daniel Forro On May 7, 2017, at 6:05 AM, Takis belzrebuth@yahoo.com
                                  Message 17 of 21 , May 7, 2017
                                    I use tape stripes over the cable near the connector and write down
                                    the connector number.

                                    Daniel Forro


                                    On May 7, 2017, at 6:05 AM, Takis belzrebuth@...
                                    [yamahablackboxes] wrote:

                                    > Great tip on that video about the pcb connectors.I remember putting
                                    > different color dots on each one before realising each one is
                                    > unique..!
                                  • Hal
                                    ... Smart move! I usually take a lot of photos (aren t digital cameras great?) whenever I disassemble or modify any gear. That way I know where each connector,
                                    Message 18 of 21 , May 7, 2017
                                      On 07/05/17 11:43, Daniel Forró danforcz@... [yamahablackboxes] wrote:
                                      > I use tape stripes over the cable near the connector and write down
                                      > the connector number.
                                      >
                                      > Daniel Forro
                                      >
                                      > On May 7, 2017, at 6:05 AM, Takis belzrebuth@...
                                      > [yamahablackboxes] wrote:
                                      >
                                      > > Great tip on that video about the pcb connectors.I remember putting
                                      > > different color dots on each one before realising each one is
                                      > > unique..!


                                      Smart move!
                                      I usually take a lot of photos (aren't digital cameras great?) whenever
                                      I disassemble or modify any gear. That way I know where each connector,
                                      screw or whatever goes, their polarity/direction and any details I might
                                      otherwise forget. It's also great for documenting things for others in
                                      forums like this one :-)
                                      Labelling connectors is a great suggestion in addition to that.

                                      The video was great BTW, Takis! Upon further inspection the PCB didn't
                                      go far underneath the keyboard, so it was easy to remove, and the video
                                      helped a lot.

                                      I think I'm going to go with Daniel Forró's suggestion: to drill a new
                                      hole for one of the pins of the CR-2032 battery holder. Fortunately the
                                      grounding trace on the rear of the PCB is big enough to allow for a new
                                      hole. By carefully bending the nearby transistor I can just about
                                      squeeze the holder in among it, the capacitor and connector around the
                                      battery area. I'll take some pictures and post here once I'm done.

                                      Hal
                                    • Hal
                                      ... That advice was perfect for me and made things a whole lot easier. I continued to use the + hole for the battery holder and drilled a new hole for - (the
                                      Message 19 of 21 , May 11, 2017
                                      On 06/05/17 17:15, Daniel Forró danforcz@... [yamahablackboxes] wrote:

                                      > 1. It is possible to buy the battery with solder pins with exact width
                                      > for DX7.
                                      >
                                      > 2. If not, there's a possibility to make new hole(s) in PCB for
                                      > different size. If I remember well the soldering pad is enough big, at
                                      > least for one pin...


                                      That advice was perfect for me and made things a whole lot easier.
                                      I continued to use the + hole for the battery holder and drilled a new
                                      hole for - (the grounding plane on the solder side was wide enough to
                                      allow it), and now the synth is working perfectly and there's no chance
                                      it'll get loose.

                                      So here's a quick rundown of how I replaced the dead original DX-7
                                      batteru with a CR-2032 battery holder and of course a new (quality
                                      brand) CR-2032 battery (in case someone reading is interested in doing
                                      the same). Also see the enclosed photos:

                                      1) Power off and unplug the synth.
                                      Open up the DX-7 (original version) by removing the four screws on the
                                      sides of the faceplate (2 on each side). Also remove the screw on the
                                      back, next to the power switch.

                                      2) Locate the DX-7 circuit board. Ensure you're grounded or have
                                      discharged yourself of any static electricity.
                                      Disconnect all the connectors attached to it (taking multiple photos
                                      will help aid you in which connector goes where when re-assembling
                                      again), then remove the screws which hold the PCB which finally will
                                      allow you to remove it from the synth.

                                      3) use pliers to carefully cut the battery pins off (do not de-solder
                                      them as the possibility of over-heating or short-circuiting the pins can
                                      cause them to explode. Then remove the remainder pins with a solder
                                      sucker or similar.

                                      4) put the battery holder in place with the + pin (observe the polarity
                                      of the battery holder!) and try to find out where to out the - pin,
                                      preferrably in a position where the battery holder goes all the way down
                                      to the PCB. You may need to bend and wiggle the transistor and/or
                                      capacitor next to the battery so that it'll fit and won't obstruct the
                                      multi-pin connector nearby. Use a pen to mark here the - pin should go.

                                      5) check and double-check that the marked spot is correct before
                                      drilling. Hold the PCB up to a light source and ensure that - pin will
                                      be on the - PCB trace (ground plane) and not somewhere else.
                                      When you're sure, drill a small hole to fit the battery holder pin
                                      (around 1mm or perhaps a little bigger if I'm not mistaken).

                                      6) On the solder side, use a small and sharp screwdriver, knife or
                                      whatever to scratch away a little of the protective layer on the ground
                                      plane around the new hole (so as to allow soldering).

                                      7) Put the battery holder in place, trying to wiggle it in between the
                                      nearby transistor, capacitor and connector. Finally, solder it in place
                                      at both the + pin and the - pin. Ensure you get good solder connections.

                                      8) You might have noticed there's a suspiciously large "blob" of solder
                                      in the battery area. This is simply two solder pads joined together
                                      (probably acting as an extra safety measurement when soldering in place
                                      the original battery so as not to short circuit it). If you removed it
                                      or it's for any reason gone, please solder these pads together again
                                      using a generous amount of solder, or a tiny bit of wire.

                                      9) Put the PCB back in place inside the DX-7, mount the screws and
                                      re-attach all the connectors.

                                      10) insert the new battery. The job is just about done!

                                      11) power up the synth and do a brief test. The message "Not ready!
                                      Change battery!" should be gone. If that's not the case, please re-check
                                      the battery holder connections.

                                      12) when everything works as intended, put the screws holding the front
                                      panel in place.


                                      Hal
                                    • Daniel Forró
                                      Congratulations! I m glad my advice was useful! Your description is perfect. I would add only these points: - If the contents of the memory (internal patches)
                                      Message 20 of 21 , May 11, 2017
                                        Congratulations! I'm glad my advice was useful!

                                        Your description is perfect. I would add only these points:

                                        - If the contents of the memory (internal patches) is not lost due
                                        weak battery, and not yet saved, transmit it as SysEx, save and after
                                        the battery replacement is done, return data to the instrument. Or
                                        save them to RAM cartridge if you have one.

                                        - For additional safety use special antistatic grounded pad and
                                        connect your hand to it with a bracelet and cable.

                                        Daniel Forro



                                        On May 12, 2017, at 7:57 AM, Hal my_list_address@...
                                        [yamahablackboxes] wrote:

                                        > On 06/05/17 17:15, Daniel Forró danforcz@...
                                        > [yamahablackboxes] wrote:
                                        >
                                        >> 1. It is possible to buy the battery with solder pins with exact
                                        >> width
                                        >> for DX7.
                                        >>
                                        >> 2. If not, there's a possibility to make new hole(s) in PCB for
                                        >> different size. If I remember well the soldering pad is enough big,
                                        >> at
                                        >> least for one pin...
                                        >
                                        >
                                        > That advice was perfect for me and made things a whole lot easier.
                                        > I continued to use the + hole for the battery holder and drilled a new
                                        > hole for - (the grounding plane on the solder side was wide enough to
                                        > allow it), and now the synth is working perfectly and there's no
                                        > chance
                                        > it'll get loose.
                                        >
                                        > So here's a quick rundown of how I replaced the dead original DX-7
                                        > batteru with a CR-2032 battery holder and of course a new (quality
                                        > brand) CR-2032 battery (in case someone reading is interested in doing
                                        > the same). Also see the enclosed photos:
                                        >
                                        > 1) Power off and unplug the synth.
                                        > Open up the DX-7 (original version) by removing the four screws on the
                                        > sides of the faceplate (2 on each side). Also remove the screw on the
                                        > back, next to the power switch.
                                        >
                                        > 2) Locate the DX-7 circuit board. Ensure you're grounded or have
                                        > discharged yourself of any static electricity.
                                        > Disconnect all the connectors attached to it (taking multiple photos
                                        > will help aid you in which connector goes where when re-assembling
                                        > again), then remove the screws which hold the PCB which finally will
                                        > allow you to remove it from the synth.
                                        >
                                        > 3) use pliers to carefully cut the battery pins off (do not de-solder
                                        > them as the possibility of over-heating or short-circuiting the pins
                                        > can
                                        > cause them to explode. Then remove the remainder pins with a solder
                                        > sucker or similar.
                                        >
                                        > 4) put the battery holder in place with the + pin (observe the
                                        > polarity
                                        > of the battery holder!) and try to find out where to out the - pin,
                                        > preferrably in a position where the battery holder goes all the way
                                        > down
                                        > to the PCB. You may need to bend and wiggle the transistor and/or
                                        > capacitor next to the battery so that it'll fit and won't obstruct the
                                        > multi-pin connector nearby. Use a pen to mark here the - pin should
                                        > go.
                                        >
                                        > 5) check and double-check that the marked spot is correct before
                                        > drilling. Hold the PCB up to a light source and ensure that - pin will
                                        > be on the - PCB trace (ground plane) and not somewhere else.
                                        > When you're sure, drill a small hole to fit the battery holder pin
                                        > (around 1mm or perhaps a little bigger if I'm not mistaken).
                                        >
                                        > 6) On the solder side, use a small and sharp screwdriver, knife or
                                        > whatever to scratch away a little of the protective layer on the
                                        > ground
                                        > plane around the new hole (so as to allow soldering).
                                        >
                                        > 7) Put the battery holder in place, trying to wiggle it in between the
                                        > nearby transistor, capacitor and connector. Finally, solder it in
                                        > place
                                        > at both the + pin and the - pin. Ensure you get good solder
                                        > connections.
                                        >
                                        > 8) You might have noticed there's a suspiciously large "blob" of
                                        > solder
                                        > in the battery area. This is simply two solder pads joined together
                                        > (probably acting as an extra safety measurement when soldering in
                                        > place
                                        > the original battery so as not to short circuit it). If you removed it
                                        > or it's for any reason gone, please solder these pads together again
                                        > using a generous amount of solder, or a tiny bit of wire.
                                        >
                                        > 9) Put the PCB back in place inside the DX-7, mount the screws and
                                        > re-attach all the connectors.
                                        >
                                        > 10) insert the new battery. The job is just about done!
                                        >
                                        > 11) power up the synth and do a brief test. The message "Not ready!
                                        > Change battery!" should be gone. If that's not the case, please re-
                                        > check
                                        > the battery holder connections.
                                        >
                                        > 12) when everything works as intended, put the screws holding the
                                        > front
                                        > panel in place.
                                      • Hal
                                        ... Thanks. Yes, the advice was exactly what I needed, so now I m going to see if I can do the same with my TX-802 and other synths. Sure beats soldering on a
                                        Message 21 of 21 , May 12, 2017
                                        On 12/05/17 02:36, Daniel Forró danforcz@... [yamahablackboxes] wrote:
                                        > Congratulations! I'm glad my advice was useful!

                                        Thanks. Yes, the advice was exactly what I needed, so now I'm going to
                                        see if I can do the same with my TX-802 and other synths. Sure beats
                                        soldering on a wire to extend one of the battery holder pins and
                                        securing it with messy hot glue to the PCB.


                                        > Your description is perfect. I would add only these points:
                                        >
                                        > - If the contents of the memory (internal patches) is not lost due
                                        > weak battery, and not yet saved, transmit it as SysEx, save and after
                                        > the battery replacement is done, return data to the instrument. Or
                                        > save them to RAM cartridge if you have one.
                                        >
                                        > - For additional safety use special antistatic grounded pad and
                                        > connect your hand to it with a bracelet and cable.

                                        Excellent advice!
                                        Yes, indeed -saving your patches first and using an antistatic grounded
                                        working surface of some kind is sound advice!

                                        Also, I should have included a visual indication of where there screws
                                        for opening up the synth and removing the PCB are.
                                        I found an online photo which I've edited to show where the 5 outer
                                        screws are, but unfortunately didn't find nor take a photo of how the
                                        PCB was mounted. But really, once you open it up it's easy to figure
                                        out. Just remember NOT to use any force (if you can't move the PCB
                                        you've forgotten a screw or two) and contrary to what I first thought,
                                        it doesn't go far underneath the keyboard.

                                        Oh, for some musical inspiration I came across this 1986 video clip of
                                        Brazilian (I think) musician Cesar Camargo Mariano playing "Um toque de
                                        funk" on what appears to be just a single DX-7, a sequencer and a Roland
                                        TR-909 drum machine: https://www.youtube.com/watch?v=H7LrpWFQ0Z0

                                        Just goes to show you don't need a whole load of gear to make fantastic
                                        music!


                                        Hal
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