Faulty PCB or blown preamp?

[quinatchie]

Hi,

I have a WD5000BMVV with the USB connector which makes no response at all when its plugged in.

From what I have read on the forum I understand the issue its likely to be the PCB, but it could also be with the preamp.

Is it ever dangerous to insulate the preamp contacts with a bit of paper and power on the drive? If not, if I do this and the disk spins, does that definitively mean the problem is with the preamp and not the PCB?

Or is the only way to know for sure to first replace the PCB (with firmware swap) and see if it works?

Many thanks

[data-medics]

It's not at all dangerous to block the preamp and see if the motor spins. If it doesn't, then it's definitely a bad PCB. However you can't ever assume that it's the only problem. I've seen plenty of cases where both PCB and heads were bad.

If the motor does spin with the PA blocked, it doesn't necessarily prove that the PCB is good but it means it's unlikely to be the problem.

[quinatchie]

Ok so the drive will spin with the preamp contacts covered. If there's a chance the fault could be entirely contained with the PCB, then I'll probably at least give replacing it a try. But the data is not valuable enough to warrant the cost of a head transplant.

Have you seen cases before where a faulty PCB still allowed the disk to spin with the contacts covered, but the preamp was ok?