I've had two real bad harddrives, and a couple of occasions
where it looked like the drive was dead, but in fact the IDE
cable was loose, or the power supply was bad(!).

In the two real cases, I used IBM's Drive Fitness Test to
test the drives on a PC. Drive Fitness Test comes on a
bootable floppy, and will find most defects, and will either
repair them or log the defect details in a file.

You can then use this logfile to create an online RMA,
where your warranty validity will be checked through
the serial number in the logfile.

In both cases, I received a new drive in a couple of weeks
directly from the manufacturer.

You can download the Drive Fitness Test and create the
online RMA through http://www.storage.ibm.com/
You will be redirected to a Hitachi site, though.

Pim