[sdiy] black flaky chip legs: what does this indicate?

[mark verbos]

If this bothers you, don’t repair any vintage EMT reverbs. Chips look like this and have their names sanded off!


Mark




> On Nov 1, 2020, at 8:19 PM, Kenny Balys <kenny at beatkamp.com> wrote:
> 
> 
> I completed a repair and had two 74LS138's with blackened
> legs. I went to pull one and it came apart. The legs are
> degraded somehow. Then on to the other 74LS138: same.
> The legs of the IC's just fell away.
> 
> What could have caused this?
> Has anyone seen something like this?
> 
> There is no Varta battery pack on the board. I have seen
> something like this on a Poly-Six.
> 
> Other IC's near these two were not the same. The circuit
> board seems to be ok.
> 
> The instrument is now functional after replacing the
> two 138's and changing a few caps.
> 
> Thanks in advance for any ideas.
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