Not completely RMA-related, but this thread reminds me of a bad experience I once had:
When I was 15 - 18, early 90s timeframe, I hired myself out for PC repair housecalls, and did pretty well for myself.
I got a call to fix a "broken PC". Went to the nice lady's house, found a genuine AT&T 386 Unix workstation. 16MHz, 8MB RAM, nice little SCSI tape drive... the works. The woman used the machine for work - early telecommuter, I guess, didn't really know much about it - all she knew was the thing had cost a fortune, more than $15,000 when it was new (and, in 1993, it was kinda old). So she was basically terrified she had broken this machine, and just of terrified of what I might have to do to fix it.
I looked at it for a while and figured out right away that its hard disk had died. No big deal. It only had a 40MB drive in it. So I explained I'd just pop out to my car for a much better 120MB drive that, along with her tape backups, would make everything OK.
So, with this woman standing over my shoulder, I popped in the new drive, installed SystemV from the tape she had, restored the backups of her personal stuff from a different tape, made sure everything worked, best as I could (first time I had ever used Unix other than SCO)... and it was fine. I shut it down.
I plopped the computer up on her kitchen counter where we could both watch as I got her final OK that everything was fixed. She fired it up... and heard the LOUDEST, most HORRIBLE head crash ever - half-height SCSI drive. Maybe lots of head crashes.
To top it off, some dust was blowing out of the PS fan. She thought the machine was on fire.
After I pried the poor woman off the ceiling, I convinced her I could get the thing working with another, different drive. Back out to my car. No more 120MB SCSI drives. But I had an old 60MB drive. I installed that. Powered it on the first time, confidently smiling to this poor woman the whole time... and heard just about the same "vacuuming up nails" noise.
She put all the parts of the computer in a box, shoved it in my arms and pushed me out the door.
Like I said, not an RMA story. Funny as I look back at it, though.