Loading ...
Sorry, an error occurred while loading the content.

LCD does not display anything

Expand Messages
  • thomasmschaefer
    Hi all, I finally got around to testing out the almost assembled SPII (only pods remain to be done. When I powered the unit on and program it, I see download
    Message 1 of 4 , Sep 17, 2011
    • 0 Attachment
      Hi all, I finally got around to testing out the almost assembled SPII (only pods remain to be done. When I powered the unit on and program it, I see download is successful. If I push an amplifier select, the relay flips. I hear staging of relays a few seconds after powerup. I checked the voltage at TP204 and it is 5.01 volts. I also adjusted the contrast with R301. Short of pulling it all apart looking for solder bridges, anyone have any ideas. Note that the LCD is lit, just no text.

      Thanks,


      Tom NY4I
    • thomasmschaefer
      The plot thickens. I noticed if I press on the left side of the LCD, it gets quite a bit brighter. Also, the LED for TX 2 blinks in concert when I push the
      Message 2 of 4 , Sep 17, 2011
      • 0 Attachment
        The plot thickens. I noticed if I press on the left side of the LCD, it gets quite a bit brighter. Also, the LED for TX 2 blinks in concert when I push the LCD> There seems to be quite a bit of give on the left side of the circuit board. Is there supposed to be something that supports the corner by the display to the front of the panel. I do not see anything obvious that is missing. I am guessing a bad connection (perhaps from shipping). When it lit up, I then tried the contrast adjustment, but that makes no difference.

        Tom NY4I

        --- In stationpro@yahoogroups.com, "thomasmschaefer" <ny4i@...> wrote:
        >
        > Hi all, I finally got around to testing out the almost assembled SPII (only pods remain to be done. When I powered the unit on and program it, I see download is successful. If I push an amplifier select, the relay flips. I hear staging of relays a few seconds after powerup. I checked the voltage at TP204 and it is 5.01 volts. I also adjusted the contrast with R301. Short of pulling it all apart looking for solder bridges, anyone have any ideas. Note that the LCD is lit, just no text.
        >
        > Thanks,
        >
        >
        > Tom NY4I
        >
      • Jim Garland
        Tom, Your symptoms suggest a bad solder connection. If the LED for TX2 blinks as you push on the LCD, then that almost surely is an intermittent connection to
        Message 3 of 4 , Sep 17, 2011
        • 0 Attachment

          Tom, Your symptoms suggest a bad solder connection. If the LED for TX2 blinks as you push on the LCD, then that almost surely is an intermittent connection to the +5V supply. The relevant +5V traces on the front panel PCB go from pins 24-25 of P307, over to C310, and then to pins 3,4, and 14 of U301.  Also, the +5V feed to the LCD goes through R316 (a 10 ohm resistor) to pin 15 of the LCD header J305.  I suggest you check all those solder joints, as well as all the joints on the LCD header (both ends). Since pushing on the display causes an intermittent problem, I’d guess there’s an unsoldered connection somewhere, or a cold solder joint. Let me know what you find.

          73,

          Jim W8ZR

           


          From: stationpro@yahoogroups.com [mailto:stationpro@yahoogroups.com] On Behalf Of thomasmschaefer
          Sent: Saturday, September 17, 2011 10:46 AM
          To: stationpro@yahoogroups.com
          Subject: [stationpro] Re: LCD does not display anything

           

           

          The plot thickens. I noticed if I press on the left side of the LCD, it gets quite a bit brighter. Also, the LED for TX 2 blinks in concert when I push the LCD> There seems to be quite a bit of give on the left side of the circuit board. Is there supposed to be something that supports the corner by the display to the front of the panel. I do not see anything obvious that is missing. I am guessing a bad connection (perhaps from shipping). When it lit up, I then tried the contrast adjustment, but that makes no difference.

          Tom NY4I

          --- In stationpro@yahoogroups.com, "thomasmschaefer" <ny4i@...> wrote:

          >
          > Hi all, I finally got around to testing out the almost assembled SPII
          (only pods remain to be done. When I powered the unit on and program it, I see download is successful. If I push an amplifier select, the relay flips. I hear staging of relays a few seconds after powerup. I checked the voltage at TP204 and it is 5.01 volts. I also adjusted the contrast with R301. Short of pulling it all apart looking for solder bridges, anyone have any ideas. Note that the LCD is lit, just no text.
          >
          > Thanks,
          >
          >
          > Tom NY4I
          >

        • thomasmschaefer
          Thanks Jim. The chap I bought it from did say it was built except for the pods but I think he forgot to solder the front side of the LCD header. Just above the
          Message 4 of 4 , Sep 17, 2011
          • 0 Attachment
            Thanks Jim.

            The chap I bought it from did say it was built except for the pods but I think he forgot to solder the front side of the LCD header. Just above the LCD, it was simply NOT soldered. Unless the PIC went bad, I don't see how it could have ever worked.

            I did take the front panel partially apart enough to solder the header. I have voltage where I am supposed to but still no display. I also do not have any CW being sent even though the relays are clicking upon startup. It does appear to program just fine. Have you ever seen a similar issue if there was an issue with the PIC?

            Short of that, I will have to disassemble the whole front and recheck every single solder joint. So, the cautionary tale of not knowing how it was put together before you. :)

            Thanks,

            Tom NY4I
            --- In stationpro@yahoogroups.com, "Jim Garland" <4cx250b@...> wrote:
            >
            > Tom, Your symptoms suggest a bad solder connection. If the LED for TX2
            > blinks as you push on the LCD, then that almost surely is an intermittent
            > connection to the +5V supply. The relevant +5V traces on the front panel PCB
            > go from pins 24-25 of P307, over to C310, and then to pins 3,4, and 14 of
            > U301. Also, the +5V feed to the LCD goes through R316 (a 10 ohm resistor)
            > to pin 15 of the LCD header J305. I suggest you check all those solder
            > joints, as well as all the joints on the LCD header (both ends). Since
            > pushing on the display causes an intermittent problem, I'd guess there's an
            > unsoldered connection somewhere, or a cold solder joint. Let me know what
            > you find.
            >
            > 73,
            >
            > Jim W8ZR
            >
            >
            >
            > _____
            >
            > From: stationpro@yahoogroups.com [mailto:stationpro@yahoogroups.com] On
            > Behalf Of thomasmschaefer
            > Sent: Saturday, September 17, 2011 10:46 AM
            > To: stationpro@yahoogroups.com
            > Subject: [stationpro] Re: LCD does not display anything
            >
            >
            >
            >
            >
            > The plot thickens. I noticed if I press on the left side of the LCD, it gets
            > quite a bit brighter. Also, the LED for TX 2 blinks in concert when I push
            > the LCD> There seems to be quite a bit of give on the left side of the
            > circuit board. Is there supposed to be something that supports the corner by
            > the display to the front of the panel. I do not see anything obvious that is
            > missing. I am guessing a bad connection (perhaps from shipping). When it lit
            > up, I then tried the contrast adjustment, but that makes no difference.
            >
            > Tom NY4I
            >
            > --- In stationpro@yahoogroups.com <mailto:stationpro%40yahoogroups.com> ,
            > "thomasmschaefer" <ny4i@> wrote:
            > >
            > > Hi all, I finally got around to testing out the almost assembled SPII
            > (only pods remain to be done. When I powered the unit on and program it, I
            > see download is successful. If I push an amplifier select, the relay flips.
            > I hear staging of relays a few seconds after powerup. I checked the voltage
            > at TP204 and it is 5.01 volts. I also adjusted the contrast with R301. Short
            > of pulling it all apart looking for solder bridges, anyone have any ideas.
            > Note that the LCD is lit, just no text.
            > >
            > > Thanks,
            > >
            > >
            > > Tom NY4I
            > >
            >
          Your message has been successfully submitted and would be delivered to recipients shortly.