Boss SD-1 with JCR4558D "black pins"???

[Old_Iron]

I just received from Japan a SD-1 with the JCR4558D chip and, as the pictures can tell, the IC pins are painted flat black, does anyone have ever seen one like that?

There are marks of re-soldering, but they are from 2 transistors, the chip solders seems unmolested.

I took this first picture, the second is from the sellers page at ebay (because it is better than mine):

Click in the pics to see it big at postimage:

[laurie]

The black isn't paint. It is corrosion. It is very common on old electronics - particularly integrated circuit legs.

It is caused by age and/or environmental conditions. My pinball machine from 1979 has that on nearly all the integrated circuit legs on the main board - caused by a leaking NiCad battery pack years ago. When I bought the machine I pulled the integrated circuit chips (they were socketed) and cleaned the legs as best I could using a brass-bristle brush, but it was working fine without that.

On your pedal C7 *might* be leaking a little and contributing. C7 is in the effected signal path so if it was leaking the sound would be degraded. So probably not that.

If the pedal spent a long time near the ocean this can also happen.

Bottom-line? If it was mine I'd leave it.

The transistors that were replaced are the output FET switch and output buffer. I've never (ever) seen a FET fail, so perhaps the person doing the repair was hunting for something else. Again, I'd leave it. Because I'm a bit fastidious about this stuff I'd clean the flux off around those transistor repairs with some flux-remover, but it's not needed.

[Old_Iron]

Thank you very much Laurie.

I never saw a thing like that before.

Even though the IC solders looks untouched, I was afraid it could be a replaced fake opamp.