IBM 6151 Maintenance And Service Manual page 171

Noise Problem PIC 0050
Use this PIC to find the FRU that is causing a loud noise.
Step 1
The device causing the noise can be identified by removing devices
from the system unit.
IS THE NOISE COMING FROM THE SYSTEM UNIT?
NO
Go to "Step 5" on page 3-0050-5.
YES
Continue on the next page.
(6/88) Problem Isolation Charts
3-0050-1