All capacitors were removed with
"twisting" method. I don't have hot tweezers to desolder large SMD capacitors and I'm afraid I would damage more pads if I used a single soldering iron. Almost all the traces left in place, I lifted just two pads which is not bad having almost hundred caps and all these leakages which could damage everything around.
After all capacitors were removed I had to clean all the acid residue. I found a lot of PCB cleaning stories. Seems that most popular way is to use Simple Green general purpose cleaner.
Simple Green + toothbrush + baking oven at about 150F made it virgin clean.
All capacitors are replaced with new low ESR leaded ones.
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| Before caps replacement |
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| After all the caps are replaced. Still have Acquisition board fail... |
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| Error log shows a mysterious error |
I still have failed acquisition test, but scope seems to be working.
Unfortunately I couldn't find where the problem can be. The only suspicious area is around U1602, where were a lot of corrosion. I replaced this opamp with a new one but could not find where one of the legs connected. Seems to be a broken trace. I would be happy to fix it but could not find where to connect it. Need to try to find out...
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| It looked not very nice... |
But I think I can live with non-calibrated scope.
