IBM 6151 Maintenance And Service Manual page 376

Step 6
1. Set the power switch on the system unit to Off.
2. Disconnect the power connector at the cooling fan.
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.
AJZBlf,9
IS THE POWER-ON INDICATOR ON?
YES Exchange the cooling fan assembly; then connect any
connectors that are disconnected. Go to "Step 14" on
page 3-8800-14.
NO Continue on the next page.
3-8800-6 Service Manual