Re: Dark deposit on pins near leaking SMD electrolytic caps


Ed Breya
 

The dark stuff is probably mostly iron (Fe+3) compounds from the steel in the IC leadframe. The electrolyte from the capacitor plague results in all sorts of reactions - galvanic, just from the different metals sitting there, and electrolytic, driven by currents when stuff is powered up. It makes a real mess, and has likely ruined countless pieces of equipment. I have two Tek scopes out of commission from it. One (TDS540 I think) is because it's so tedious to track down the damage, and the other (TDS820) is because I can't find schematics needed to track down the damage, making it nearly impossible.

Ed

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