IBM RT PC 10 Hardware Maintenance And Service page 117

Step 5
1. Set the system unit power switch to Off.
2. Connect the power connector to the diskette drive.
3. Be sure the power has been off 30 seconds, then set the power switch
on the system unit to On.
4. Wait 15 seconds, then answer the following question.
l:JD
3-72 Service Manual
IS THE POWER-ON INDICATOR ON?
NO Exchange the diskette drive. This completes the repair.
YES Exchange the fixed-disk drive. This completes the repair.