IBM 6151 Maintenance And Service Manual page 174

Step 4
Either the diskette drive or the fixed-disk drive is causing the
problem.
1. Set the power switch on the system unit to Off.
2. Connect the fixed-disk drive.
3. Set the power switch to On.
DO YOU STILL HAVE A NOISE PROBLEM?
YES The fixed-disk drive is failing.
1.
Connect the diskette drive.
2. Exchange the fixed-disk drive.
3. Run the System Checkout.
4. This completes the repair.
NO
The diskette drive is failing.
1.
Exchange the diskette drive.
2. Run the System Checkout.
3. This completes the repair.
3-0050-4 Service Manual