Hi Guys,
Update time. Finally got in (stripped torx heads are no fun - drilled it out.)
I went to J119 and checked the voltages. Two points failed:
J119-5 (-4.965 to -5.035) measured -4.53
J119-11 (-7.88 to -8.12) measured -6.30
To answer Siggi's question, I'm comfortable around old computers (6502's and 8086/88's) and replacing both chips and discrete components.
I don't think I am properly measuring total p-p ripple; my values seem significantly less than (a factor of 10) the tolerances. AND I have no clue how to measure the p-p at 2x line frequency. I suspect it's obvious, but I'm at a total loss.
All the boards appear to be from 1987 and populated with late '88 chips & hybrids. Not a single smd to be found (correction, a small daughter card about 0.5" x 2" near the top right of the main board).
-Stefan
