Work on the internal disk drive of IBM 1130 - part 1

RESTORED 1130 POWER RAIL LEVEL LEADING TO NEW SYMPTOMS When working on the disk drive attempting to make the adjustments for seek behavior, I checked the voltage at a pin that the Field Engineeering Maintenance Manual (FEMM) suggested be tested. The expected level was 8V but I found it at 6.2V. I verified the incoming power rails - +3V, -3V and +6V - only to find that the last was only at 5V. I…