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I removed the CPU and display boards from the case, and cleaned up the goo left by some foam between the keyboard’s keys.
Wires for providing power added:
GND black
+5v Red
+20VFX brown
+5VFX UNreg (connected to R110 1ohm then to large cap C110 +)
I connected the CPU board to a 5V power supply and checked current consumption (around 1.6A). Nothing got hot, so I checked the CPU clock (worked) and the R/W and address lines. The CPU seems to run.
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