Can’t Find Intermittent Problem In Electronic Components?
Now you have confirmed that the vertical section is giving intermittent problem because the moment you use the handle of the screw driver to gently knock on the board and the display goes back to normal again. You have spent your precious time to test on the components and hope to locate the bad component but you found all of them to be okay. Next you had replaced all of the components one by one and hope to find out which components that give intermittent problem but again the intermittent problem still exist even though you have try hard to solve it.
If you have replaced all of the components and still could not solve the problem then it is time for you to look at the circuit track for hairline crack. You would be surprise with the help of magnifying glass you could see such a tiny crack in between the circuit line. Some circuit boards were just too thin and easily breaks the circuit line/trace. Get a magnifying glass with the X10 range as you could easily see the crack (if there is a break in the line). Once you have located the break in the line you can always solder a wire (use a small wire) across it to make connection again.
Waleed
April 21, 2009 at 5:36 pm
I could relate to that. many times I faced this problem and I bought a big lens with light that comes with a stand. you could hock it up to the table and move it any where it is needed. also bought an hand held lens with light to help you see such problem. so far it is working fine. before i knew this, this kind of problems were giving me a lot of headache to figure out the problem.
admin
April 21, 2009 at 8:45 pm
HI Waleed,
You were right getting those big lense with light will help a lot in this kind of repair
Jestine
john from preher-tech.com
April 22, 2009 at 5:12 am
cracks in the traces can make you pull your hair out..I use opti-visors and I always carry a 30X jewelers loop to help me look at PCB for cracks , bad solder connections and to read SMD components...another thing to watch for especially on the vertical I.C. is when the pads that the leads solder to, separate from the trace...in this case I use a razor blade to scrape open the trace right next to the pad, and then solder the exposed trace to the pad and lead, closing the crack that is where the trace meets the pad, it helps to apply some flux to the newly exposed trace to make the solder flow to it.....
admin
April 22, 2009 at 10:41 pm
Hi John,
Wow! Thanks for the good information!
Jestine