[sdiy] SAJ110 help please

[Bob Weigel]

I had this solina all working and sold it on ebay.  Then it started 
manifesting this on my final check again.  Some may recall that I had to 
remove and socket 6/8 of the divider chips in this one and work through 
like 20 chips which mostly worked in other things (a crumar organizer 2 
we were working on at the time...) but mostly didn't work in the 
solina.  I barely had enough chips to get it working moving them around!

Well something degraded and pin 9 started giving a disharmonic 
overlapping of two frequencies kind of sound.  I swapped chips from 
another location and the same pin fouls up in another location so it 
seems to follow the chip.  However I just cleaed out 7 more from an old 
italian ep... and they all do the same thing (or worse..one had another 
bad pin that was totally missing but WORKED on the pin that was bad on 
the others! Great...)

Am I just the victim of extremely crummy luck here?  I added a local 
filter cap on that board..did no good. Voltage is -7.7V on pin 1 and I'm 
about to rip chips out of another one of these scrap electric pianos we 
had in storage.  Has anyone ever seen anything like this?  (Oh and I 
should add..I disconnected everything but the two resistors from the pin 
and it still did it...so it's not  the capacitor we know that is also 
connected to that pin causing some kind of loading effect.  Several 
thousand ohms impedence of resistances hooked to it which should isolate 
it from anything on the other side well enough to allow them to drive 
the point of the output pin anyway.  But again like I say it's 
definitely following the chip from socket to socket.  But I have..a 
whole pile of these chips and...they work in another unit most of them 
which drives us back to 'power supply' I'd think.  What am I missing?)

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