Replacing an Internal Disk Drive CRU

7 Simultaneously tighten both thumbscrews on the faceplate of the disk drive
CRU to seat the CRU against the backplane. Do not over-tighten the
thumbscrews.
Once the CRU is properly connected to the backplane, a power-on self-test
(POST) runs. The amber LED becomes lit, then flashes, but upon successful
completion of the POST, only the green power-on LED remains lit.
If the POST fails, try reseating the CRU. If the POST fails a second time, try
installing a different disk drive CRU.
8 Detach the grounding clip of your ESD wriststrap.
9 Close and lock the enclosure door.