Re: Dark deposit on pins near leaking SMD electrolytic caps


greenboxmaven
 

I have restored some Sony video recorders that were loaded with the bad condensers. I made notes about ratings and placement, removed them all, and scrubbed the boards with hot soapy water. After a good rinse and drying, I re-tinned the spots where the condensers go, and repeated the wash. After that, installed the new condensers. I had complete success.

Bruce Gentry, KA2IVY

On 2/9/21 19:13, Ozan wrote:
Hello,
Does anyone know the chemical composition of the dark deposits on IC pins that are close to leaking SMD caps? What is the best way to clean them? Litmus paper shows base (hard to tell because it gets stained by the deposit). I couldn't find a good solvent for it.

Here is a picture from a TDS520A
https://groups.io/g/TekScopes/photo/260554/0?p=Name,,,20,1,0,0

Interestingly sometimes one or two pins are covered but neighboring pins are OK (maybe voltage at the pin making a difference?). I have seen this in CPU card of 2467B, both acquisition and CPU cards of TDS520 and TDS520A.
Ozan




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