Finally had time to track this down. I'm passing this along for anyone who 
might have this happen down the road.

The contrast POT (VR1) was not the problem. The 100k resistor (R10) which is 
part of the contrast circuit went bad. I took it out to measure the value and 
instead of 100k my meter said 1.7meg, so 17 times what the value should have 
been..

I can only speculate as to why, but since that resistor is right next to the 
memory backup battery I think that's the key. Long ago this battery leaked 
before I changed it out. Looking at R17, I could see discoloration on the 
leads. 

So one small resistor was all I needed to swap out and this machine is back up 
and running.

Kurt McCullum

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