@Harvey
Measured voltage across 0.33ohm R624 = ~0.35V. So ~1A. Seems normal.
One thing I learned reading through the circuit description is that 5V supply is referenced from the -22V rail. Would it be a good idea to inject -22V to see if this brings the 5V rail into sepc?
I was looking at the display/counter circuit more closely - everything was looking good until I got to the state generator timing relationship waveforms. They all match except pin 12 438D - there is no reset pulses. Also, pins 6 and 7 to counter U490 are low. According to the ciruit description, these should be high.
Still need to do more digging/inspecting. Thanks for everyone's help!
-Frank
Frank Mashockie