WD2500JB spinning down after short time or not up at all

[shaun]

Hi all,

I am not actually a DR pro, but more in special electronics of all kind, so I get all the hard disks, flash memories aso that have suffered from surges, wrong polarity or mechanical abuse.
Now I have a WD here that may well fall into this range.
It was run in a cheapo USB 2.0 external enclosure, powered from 12 volts externally; the +5V were supplied by an internal step down regulator. The latter has failed, actually the single output cap has caused instability of the control loop.
The voltage has not got that high that I would suspect actual component destruction, but nonetheless the drive only spins up shortly, identifies itself to the system and shuts off again.
Sometimes it tries to spin up again for one or two times before it gives up.
No clicking or whatever, only the inital seek and bootstrapping is heard.
It needs some time after being switched off to get the drive spinning again.

For now, I have not removed the PCB, but I wanted to discuss this one with the pros from the DR scene. Maybe I can help you out with some electronics problem somewhen, apart from redesigns in industrial control applications we do component level troubleshooting of gear of all kind, including mainboards from the late 70s to now.

[DRNJ]

Remove the drive from USB case and hook it up to your desktop computer.
If it works there you need a new USB case.
If it does not work you need to fix your drive's PCB.

[shaun]

Ok, I agree, I did not make this clear in the first place: the drive is of course showing this behaviour on my well regulated bench power supply.
At the moment my plan would be to locate an identical PCB with the same controller and cache size (if this does matter) and swap the 1Mbit serial flash.

[DRNJ]

If you had PC-3000 or Salvation Data I would suggest a few things to try.
I assume you do not have one so your only option is PCB and ROM swap.
You just have to match the first 13 digits on the bar code sticker on the black connector.
Swap the ROM and hope it fixes your problem.

[shaun]

Hi,
thanks for your reply.
No, unfortunately I don't have PC3000.
Is it still that oddly priced - rest of teh world pays ten times the price than the own folks or something like that? No doubt, there's much work in PC3000, but it is also somewhat hard to claim copyrights on a product based on reverse engineered or NDA information which use is also illegal in many countries. So what, it's a great product, I've seen it in action twice, but in the very beginnings. I think it has become even better.

Back to my problem: the disk works, files are accessible but somewhen (not at a particular sector position but more at a particular temperature and/or time of operation) it stops, eventually shuts down and when shut down will not come up for minutes even after the power has been removed for a minute or so. That is what makes me think primarily of the PCB, because the motor is not energized at all (checked with scope). Platter defects can lead to shutdown after they have actually been read, which is not the reason here.
I'll order a drive with a matching PCB and give it a try.

Thanks folks!