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Technician

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  • Hudson T Clark
    I don t know I m starting to get scared. I m taking a while to get my 2 year degree in electronics, but it is coming very near now. I m insanely paranoid I
    Message 1 of 16 , Apr 25, 2003
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      I don't know I'm starting to get scared. I'm taking a while to get my 2
      year degree in electronics, but it is coming very near now. I'm insanely
      paranoid I won't be able to do my job (I get B's and A's I'm fine in
      school). But can someone tell me, when you troubleshoot boards do you
      normally just start checking to see whats not working? like check all the
      components and make sure they are doing what they should be?
    • csakima
      For me, what I do is first compare what the board s SUPPOSED to do ... with what it DOES (wrongly) do. Then use this information to narrow down which block
      Message 2 of 16 , Apr 25, 2003
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        For me, what I do is first compare what the board's SUPPOSED to do ... with
        what it "DOES" (wrongly) do.

        Then use this information to narrow down which "block" (in the "block
        diagram") is at fault (and which is obviously NOT).

        I then go from there.

        Curtis
        Electronics Technician by Trade.


        Get your free newsletter at
        http://www.ezinfocenter.com/3122155/NL


        ----- Original Message -----
        From: Hudson T Clark <dark_archon1@...>

        I don't know I'm starting to get scared. I'm taking a while to get my 2 year
        degree in electronics, but it is coming very near now. I'm insanely paranoid
        I won't be able to do my job (I get B's and A's I'm fine in school). But can
        someone tell me, when you troubleshoot boards do you normally just start
        checking to see whats not working? like check all the components and make
        sure they are doing what they should be?
      • Hudson T Clark
        Interesting way of logic but ya pretty much what I said. =) I suppoe knowing operation theory is good to like knowing a lot about electronics in general...?
        Message 3 of 16 , Apr 25, 2003
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          Interesting way of logic but ya pretty much what I said. =)

          I suppoe knowing operation theory is good to like knowing a lot about
          electronics in general...?
        • sjhartley98
          Most people can learn to trouble shoot a piese of equipment on the large scale. I work for the Navy as a Machinest Mate in ship propulsion, and we are tought
          Message 4 of 16 , Apr 25, 2003
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            Most people can learn to trouble shoot a piese of equipment on the
            large scale. I work for the Navy as a Machinest Mate in ship
            propulsion, and we are tought to break the system down into large
            components or sections. In electronics it is the same way there are
            a general set of questions for any system that need to be answered
            when a problem arrises. Thoes questions will come from your school,
            practical experience, and the biggest one, MISTAKES. I am finding
            that the better engineers are the ones that have the right list of
            questions but not necessarly the the most indepth understanding of
            how every component works. Funny enough the #1 question that i see
            misseed in the electrical side of my feld is "is the power on? or Is
            the fuse blown?" People spend hours trouble shooting to find a switch
            off or a power supply fuse blown. Unfrotunatly we stop on the big
            scale most of the time.. Power supply broken... replace the card.
            instead of finding the damaged dioed. Maby the civilian sector is
            different I am not sure, but you always start by looking at the
            general groups of components that make up a system to get a bering on
            where the problem lies then you hone in on the specific problem.




            --- In Electronics_101@yahoogroups.com, Hudson T Clark
            <dark_archon1@j...> wrote:
            > Interesting way of logic but ya pretty much what I said. =)
            >
            > I suppoe knowing operation theory is good to like knowing a lot
            about
            > electronics in general...?
          • Hudson T Clark
            Yeah that sounds like maybe someone more then just the navy technicians do! But thanks for the grate reply =).
            Message 5 of 16 , Apr 25, 2003
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              Yeah that sounds like maybe someone more then just the navy technicians
              do! But thanks for the grate reply =).
            • Hudson T Clark
              Wow that was helpful thank you.
              Message 6 of 16 , Apr 25, 2003
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                Wow that was helpful thank you.
              • Hudson T Clark
                WOW! Thank you for the grate reply guy that was very helpful. It sounds very logical... troubleshooting that is. I basically need a schematic/diagram from what
                Message 7 of 16 , Apr 26, 2003
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                  WOW! Thank you for the grate reply guy that was very helpful. It sounds
                  very logical... troubleshooting that is. I basically need a
                  schematic/diagram from what I understand. After this I just started from
                  there and come up with a method of checking the board like you suggested
                  starting a visual scan from the top left corner to the bottom right
                  corner. Very interesting indeed. I guess like you said after visually
                  inspecting the board I would check for over heating components, and make
                  sure traces are ok, etc. This is very helpful you all! I want to be an
                  electronics technician I could probably make it as an engineer but I want
                  to be a technician. I like to joke around and say we are better then you
                  big bad engineers if you are so perfect why are you fixing everything you
                  design he he he. =0)

                  Like I said thank you very much everyone I can't believe I'm getting such
                  positive responses I expecting this post to be over looked and I wasn't
                  expecting this many grate replies. Btw, keeping a notebook sounds like a
                  grate idea. Especially if I'm working with a specific collection of
                  systems. Like if I work at one place and work on ummm like sony tv's or
                  something and I kept a "sony tv troubleshooting" book that I wrote all of
                  my experiences in while working with sony tv's. Then if I went to apply
                  for some job fixing more sony tv's I can just slap that big (hopefully
                  thick) notebook down on the table and be like I'm ready! gimme a job! =).
                • Brian Hoskins
                  Hello Hudson ... Knowing the Electronics is the basis of a good technician - just as knowing the alphabet allows you to decipher words, knowing the underlying
                  Message 8 of 16 , Apr 26, 2003
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                    Hello Hudson

                    On 26-Apr-03, you wrote:

                    > Interesting way of logic but ya pretty much what I said. =)
                    >
                    > I suppoe knowing operation theory is good to like knowing a lot about
                    > electronics in general...?

                    Knowing the Electronics is the basis of a good technician - just as knowing
                    the alphabet allows you to decipher words, knowing the underlying
                    electronics will allow you to figure out the circuits you will come across
                    in fault finding.

                    Fault finding is an "aquired" skill, gained from a mix of technical ability
                    and experience. There's a "knack" to fault finding that you can't really
                    teach anyone, you just have to learn it for yourself - it comes with
                    practise and experience. After a couple of years fault finding you develop
                    a.... what's the word... well it's a little bit like a sixth sense, or just
                    a new way of looking at things. You can see the symptoms and electronic
                    effects of a fault condition and immediately gain an idea of where abouts
                    the fault is likely to be.

                    Another key area in your fault finding ability will be your product
                    expereince. For example, our company sells a lot of Sanyo TVs, and as a
                    result I've gained much experience with those. For a start you become
                    familiar with the product's "common faults", and also after a while you
                    become extremely familiar with how the product itself works and it's
                    circuitry. Show me the circuit schematic for a brand new Sanyo Widescreen
                    television and I'm right at home. Show me the circuit schematic for a
                    Panasonic TV and all of a sudden I'm a little bit lost. Fault finding is
                    all down to the experience you can gain, both in fault finding skills and
                    the product itself. Starting off it's very hard, but as you become more
                    confident with the product and your skills fault finding becomes a lot
                    easier :)






                    -----
                    Brian J Hoskins
                    South Wales, UK

                    Email: BrianJHoskins@...
                    Mobile: 07967 240380

                    Amiga 040/PPC, Amiga OS3.9.
                    -----
                  • Mariss Freimanis
                    Hudson, Troubleshooting is an art all by itself. I m a EE that apprenticed as a technician during 4 summers while I went to school. It probably was the most
                    Message 9 of 16 , Apr 26, 2003
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                      Hudson,

                      Troubleshooting is an art all by itself. I'm a EE that apprenticed as
                      a technician during 4 summers while I went to school. It probably was
                      the most useful practical education I ever got.

                      Leaving aside the obvious such as being grounded in electronics and
                      fully understanding how what you are diagnosing works, here are some
                      principles I learned.

                      1) The answer is under your nose:

                      Look for the obvious. ICs placed backwards, bad solder joints, cut or
                      shorted traces, components missing. This you can find with a quick
                      visual scan and the problem is solved without even using a scope.

                      Good designs always work; if they don't, it's because 90% of the time
                      the cause is a "mechanical" problem you can see. Develop a
                      disciplined visual raster scan of the offending board. Start in the
                      upper left hand corner, scan across and down until you reach the
                      lower right hand one.

                      Keep an especially sharp lookout for joints where the solder meniscus
                      doesn't look right; a pin that isn't wetted properly should jump out.

                      2) It's under your nose (Part 2):

                      Let's say it's the remaining 10%. Check to see the inputs to the
                      board are doing what they are supposed to. It's tough to check a
                      board if say a signal generator is not generating a signal.

                      Check the supply voltages. You can't troubleshoot something if the
                      supply is missing or grossly out of spec. The same goes for outputs
                      as well.

                      3) Let your fingers do the walking:

                      You have a circuit board that has (A), a low supply voltage and (B),
                      is drawing much more supply current than nominal. This is the
                      dreaded "something is shorted across the bus" situation; could be a
                      million different components, where do I start?

                      Well, that's what fingers are for. Use one (I prefer the little one
                      because its skin is the thinnest) to feel across the components on
                      the board, looking for a hot component. That will focus your
                      attention on the troublemaker.

                      If the supply bus is near zero volts then this doesn't work as well
                      because not enough Watts are being delivered to create heat. This is
                      a tougher situation and requires sterner measures. Bypass the
                      regulator with a higher current lab supply set to the circuit
                      voltage. The higher power will reveal the culprit.

                      4) Troubleshooting is like tree:

                      Signals that enter a board branch out like a tree into a circuit and
                      do the reverese as they converge at outputs. You can start at either
                      end when something doesn't work. If you start at the input, follow
                      the good signals with a scope down each branch until you run into
                      something that isn't right.

                      5) History, History:

                      Keep a notebook. Everytime you troubleshoot a board successfully,
                      note the symptoms and the ultimate cause. Just like a properly
                      functioning circuit whose outputs are predictable based on its
                      inputs, malfunctions do the same. Though they may seem infinite, they
                      are not. A good notebook will quickly lead you to the cause of a
                      problem if it has been noted before. You will look like a genius as
                      well.

                      6) Don't give CPR to a corpse:

                      This is knowing when to quit. Say the power supply polarity was
                      reversed on a card containing a hundred ICs. Probably most are fried.
                      You are paid to economically restore a circuit to functionallity but
                      you can't do that if you must replace every IC. It's just not worth
                      it even if it proves your troubleshooting prowess.

                      Say the same problem chars the PCB. Char is carbon, it conducts
                      electricity and it has replaced the epoxy resin insulation of the
                      board. It doesn't matter that a single resistor did it. The board is
                      history.

                      Knowing when to quit is just as important as knowing how to repair
                      the repairable. There are some boards that you pull the sheet over
                      and move on to the next one.

                      Anyway, that's some of what I learned a long time ago from some very
                      smart electronic technicians.

                      Mariss



                      --- In Electronics_101@yahoogroups.com, Hudson T Clark
                      <dark_archon1@j...> wrote:
                      > I don't know I'm starting to get scared. I'm taking a while to get
                      my 2
                      > year degree in electronics, but it is coming very near now. I'm
                      insanely
                      > paranoid I won't be able to do my job (I get B's and A's I'm fine in
                      > school). But can someone tell me, when you troubleshoot boards do
                      you
                      > normally just start checking to see whats not working? like check
                      all the
                      > components and make sure they are doing what they should be?
                    • prasanna venkatesan
                      hi, If u r designing ur own circuits ,then a thorough understanding of various components is a must. both practical and theoretical.But since sufficent amount
                      Message 10 of 16 , Apr 26, 2003
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                        hi,
                        If u r designing ur own circuits ,then a thorough understanding of various components is a must.
                        both practical and theoretical.But since sufficent amount of research has been done by people around
                        the world and with enough documentation about circuits already exsists our only job is in the implementation of the circuit.This is where theory just dosen't seem to go hand in hand with practical
                        reality.
                        For trouble shooting any circuit(Assuming tht circuit is adopted from a reliable source) the following tips
                        would be useful.
                        1.Check for circuit connections before sswitching on supply.(with multimeter)
                        2.check for possible wrong connections,shorts occuring inadvertently because of bad soldering
                        3.once  u have done tht give supply.(always give a 1Kohm resistor in series with a led to positive of     supply .Led glowing would indicate the circuit is getting adequate supply.the 1kohm is for Led protection)
                        4.If the Led dosen't glow either its damaged or u have interchanged the + and - .
                        5.Immediately remove power supply and check for heating of the Ic used.In most cases reversal of supply damages the Ic.
                        6.If u still don't get the output check for voltages at diff points in the circuits(Assuming u have decent knowledge of the circuit)u can expect certain voltage drops across ccertan points.Say for instance a diode if forward biased would have a drop of 0.7 volts.A transistor when switched on willnot have any voltage drop
                        across it where as when it is open will show a  drop equal to VCC when voltage is measured across
                        the collector and emitter terminals(assuming emitter to be grounded).
                        7. if appropriate voltage drop dosen't occur either circuit connections are wrong or the particular part is
                        damaged.try changing it.
                        These are the normal procedure which anybody would follow assuming u have a perfect power supply.
                        For instance when u use TTL Ic's it is imperative tht u use a voltage supply between 4.75 volts to 5.25 volts.
                        This is from the manufacturers datasheet.For this u can use a 7805 voltage regulator.
                        8.In any electronic circuit always use a decoupling capacitor especially if the circuit comprises of a time varying signal in any form as either input or output.An example would be a clock pulse from timer given
                        to an ADC or a counter.By decoupling capacitor i mean put a 0.1microfarad and 10 microfarad between supply and ground.This is done to remove the 50hz ripple(hum) arising from the supply line and also to eliminate the ripples produced because of clock pulse.
                        9.If u have given Led as output indicator of the Ic It often happens tht Led loads the the chip.This might affect the entire circuit.Certain chips can drive Leds where as others can't.So give a resistor at the output in series with Led.
                        Well theres lot more of small techniques.All of them come with practice as the others have mentioned.
                        Trust me electronics is easy but can be time consuming.As u keep digging into it u will master trouble shooting.the above tips might be useful but these alone will not help u trouble shoot any circuit.u ll learn as u keep implementing circuits.
                        bye



                        Hudson T Clark <dark_archon1@...> wrote:



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                      • James Liddle
                        Several years ago, Bob Pease wrote a book Troubleshooting Analog Circuits (ISBN 0-7506-9184-0). It s well written, comprehensive and sensible - I highly
                        Message 11 of 16 , May 2, 2003
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                          Several years ago, Bob Pease wrote a book "Troubleshooting Analog Circuits" (ISBN 0-7506-9184-0).  It's well written, comprehensive and sensible - I highly recommend it.  Bob is a Staff Scientist at National Semiconductor, a columnist for EDN magazine, and has a very engaging writing style.
                           
                          Best Regards,
                           
                          Jim

                          Hudson T Clark <dark_archon1@...> wrote:
                          WOW! Thank you for the grate reply guy that was very helpful. It sounds
                          very logical... troubleshooting that is. I basically need a
                          schematic/diagram from what I understand. After this I just started from
                          there and come up with a method of checking the board like you suggested
                          starting a visual scan from the top left corner to the bottom right
                          corner. Very interesting indeed. I guess like you said after visually
                          inspecting the board I would check for over heating components, and make
                          sure traces are ok, etc. This is very helpful you all! I want to be an
                          electronics technician I could probably make it as an engineer but I want
                          to be a technician. I like to joke around and say we are better then you
                          big bad engineers if you are so perfect why are you fixing everything you
                          design he he he. =0)

                          Like I said thank you very much everyone I can't believe I'm getting such
                          positive responses I expecting this post to be over looked and I wasn't
                          expecting this many grate replies. Btw, keeping a notebook sounds like a
                          grate idea. Especially if I'm working with a specific collection of
                          systems. Like if I work at one place and work on ummm like sony tv's or
                          something and I kept a "sony tv troubleshooting" book that I wrote all of
                          my experiences in while working with sony tv's. Then if I went to apply
                          for some job fixing more sony tv's I can just slap that big (hopefully
                          thick) notebook down on the table and be like I'm ready! gimme a job! =).


                          To unsubscribe from this group, send an email to:
                          Electronics_101-unsubscribe@yahoogroups.com



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                        • Hudson T Clark
                          Yeah most of my teachers make fun of these big bad engineers from university that can t even use a soldering iron. My one takes pride in bashing them, seeing
                          Message 12 of 16 , May 2, 2003
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                            Yeah most of my teachers make fun of these big bad engineers from
                            university that can't even use a soldering iron. My one takes pride in
                            bashing them, seeing how he can come up with come occasion when he has
                            been called because one of them has made a really bad mistake.
                          • Hudson T Clark
                            I think it matters the place you live... I don t think its that impossiable to get work, much of my teachers show examples and even find students jobs. I saw I
                            Message 13 of 16 , May 2, 2003
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                              I think it matters the place you live... I don't think its that
                              impossiable to get work, much of my teachers show examples and even find
                              students jobs. I saw I think like one time in the some years I have been
                              in this school even a major coperation called the teacher (probably rare
                              its a community college) and was looking for graduates... I don't think
                              its that rare. I can see (I'm not a fool) that the industry is changing,
                              now its the board doesn't work toss it in the can and order a new one. I
                              know its starting more and more to be like this. I may also go to a four
                              year college which is more and more looking like a reality for me. I hope
                              I would be able to deal with the GE requirements *prays* I'm really bad
                              at learning something I don't care about. But I don't know man I think I
                              will be able to support myself as a technician. I also live in
                              california, so there are some pretty big cities here, what city do you
                              live in? If its small probably won't be any jobs... I was just wondering
                              you have to tell us more to see if its just the place you are living
                              maybe? I don't take offense to what you said I look at it as more postive
                              feedback... just helping me understand the situation more. Even if its a
                              negative situation doesn't mean I don't appreciate.
                            • manifold
                              Engaging writing style!? He s an opinionated, self important curmudgeon! and I like his articles a lot. ... Circuits (ISBN 0-7506-9184-0). It s well written,
                              Message 14 of 16 , May 2, 2003
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                                Engaging writing style!?

                                He's an opinionated, self important curmudgeon!
                                and I like his articles a lot.


                                --- In Electronics_101@yahoogroups.com, James Liddle <jliddle31@y...>
                                wrote:
                                > Several years ago, Bob Pease wrote a book "Troubleshooting Analog
                                Circuits" (ISBN 0-7506-9184-0). It's well written, comprehensive and
                                sensible - I highly recommend it. Bob is a Staff Scientist at
                                National Semiconductor, a columnist for EDN magazine, and has a very
                                engaging writing style. Best Regards, Jim
                                >
                              • manifold
                                Good luck when you decide to change from repairing to designing circuits as an engineer. The technical background can really help in the design process. Do not
                                Message 15 of 16 , May 2, 2003
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                                  Good luck when you decide to change from repairing to designing
                                  circuits as an engineer. The technical background can really help in
                                  the design process. Do not be too self conscious about being the only
                                  engineer in the company that can solder! I know what that's like.


                                  --- In Electronics_101@yahoogroups.com, Hudson T Clark
                                  <dark_archon1@j...> wrote:
                                  > WOW! Thank you for the grate reply guy that was very helpful. It
                                  sounds
                                  > very logical... troubleshooting that is. I basically need a
                                  > schematic/diagram from what I understand. After this I just started
                                  from
                                  > there and come up with a method of checking the board like you
                                  suggested
                                  > starting a visual scan from the top left corner to the bottom right
                                  > corner. Very interesting indeed. I guess like you said after
                                  visually
                                  > inspecting the board I would check for over heating components, and
                                  make
                                  > sure traces are ok, etc. This is very helpful you all! I want to be
                                  an
                                  > electronics technician I could probably make it as an engineer but
                                  I want
                                  > to be a technician.

                                  cut ------------
                                • csakima
                                  Don t mean to rain on anybody s parade ... but right now, at least in my neck of the woods ... actual technician jobs have been hard to come by. Companies
                                  Message 16 of 16 , May 2, 2003
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                                    Don't mean to rain on anybody's parade ... but right now, at least in my
                                    neck of the woods ... actual "technician" jobs have been hard to come by.
                                    Companies have (again, in my neck of the woods) have just seemed to "stopped
                                    hiring".

                                    Me, I was myself, laid off about a year ago.... from a so-called
                                    "technician" job. You know .... DMM ... Oscilloscope ... etc. And
                                    although I have been supporting myself ... it's only through a bunch of odd
                                    and end odd jobs. Nothing really .... er ... "technical". Not in the true
                                    sense of the word anyways. So "technician"-wise ... you might say that
                                    "I've been unemployed" .. "almost a year now". My buddy, who he and I
                                    were laid off at the same place (we keep in touch), is in a similar
                                    circumstance.

                                    Again, like I said .. I don't mean to rain on anybody's parade ... but I
                                    heard a "I WANT to be a technician" spoken. And thought it'd be a sin ...
                                    if I didn't speak up about "my" situation.

                                    BTW .... if any of you know of any "Tech" jobs, my number is
                                    .............................

                                    Curtis

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                                    http://www.ezinfocenter.com/3122155/NL




                                    ----- Original Message -----
                                    From: manifold <manifold_1@...>

                                    Good luck when you decide to change from repairing to designing circuits as
                                    an engineer. The technical background can really help in the design process.
                                    Do not be too self conscious about being the only engineer in the company
                                    that can solder! I know what that's like.


                                    --- In Electronics_101@yahoogroups.com, Hudson T Clark <dark_archon1@j...>
                                    wrote:

                                    WOW! Thank you for the grate reply guy that was very helpful. It sounds very
                                    logical... troubleshooting that is. I basically need a schematic/diagram
                                    from what I understand. After this I just started from there and come up
                                    with a method of checking the board like you suggested starting a visual
                                    scan from the top left corner to the bottom right corner. Very interesting
                                    indeed. I guess like you said after visually inspecting the board I would
                                    check for over heating components, and make sure traces are ok, etc. This is
                                    very helpful you all! I want to be an electronics technician I could
                                    probably make it as an engineer but I want to be a technician.
                                  Your message has been successfully submitted and would be delivered to recipients shortly.