Suggestions for cleaning hundreds of socketed chips?

Josh Dersch derschjo at msu.edu
Tue Sep 9 03:17:55 CDT 2008


Hey all --

I've gotten the power supply in one of my ND-812s running (thanks for 
the help w/the 1103 data which helped verify the voltages) and it 
appears to be within spec under load (correct voltages, no ripple in the 
output, etc...) so I powered the machine on and despite having my 
fingers crossed, the machine does not run.   (No real surprise there).   
Random lights on the front panel, and basically no response to any 
toggle switches.

I started pulling out and reseating the chips on the main CPU board and 
powered it up after every few rows, and every time the behavior was 
slightly different, so I'm fairly sure that the sockets and chips aren't 
all making good connections anymore.  Seems like solving this problem 
would be a good place to start.

The problem is that there are 25 rows of 13 chips each (all socketed), 
in very close proximity to one another.  The chips are in sockets with 
wire-wrap pins underneath -- the underside of the main CPU board is a 
maze of wire wrapping.  Most of the chips have date stamps between 1971 
and 1973, but luckily most of them aren't corroded to the point where 
they're falling apart.

How would you suggest cleaning the sockets and the chips to ensure good 
connections?

Thanks,
Josh



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