I just replaced the PCB on a drive I have with another one of the same model but the FW/PN were different because I couldn't find the exact match. I don't really care about the information on the drive this is more a learning experiment, but when i put the new PCB and plug the drive in I'm getting no power to the drive. The light turns on, but nothing happens, the disks don't spin and the head doesn't move.

The old PCB still powers up the drive but the head keeps ticking out of control, I see it just moving back and forth. So basically the old PCB powers the drive but I can't access it because the head won't relax, and the new PCB doesn't seem to do anything to the drive. Any idea whats going on here? How do I test the new PCB to see if its working?

  • I would suggest moving this to electronics.se
    – Rory Alsop
    Commented Oct 19, 2011 at 22:19
  • thats a german site that seems under construction
    – GiH
    Commented Oct 19, 2011 at 22:56
  • GiH: @RoryAlsop means electronics.stackexchange.com
    – studiohack
    Commented Oct 19, 2011 at 23:07

2 Answers 2


You mentioned you can see the heads trashing? If you have opened the disk, but not in a proper clean room your drive may be doomed. A speck of dust is all it takes to scratch the platter beyond repair. Even professional recovery centres would have difficulty recovering data in this case.

Having said that, are you sure the original PCB is bad? It could be the preamp which is actually located off the main PCB, usually on the cable that runs to the heads (see link below). Even still the disk platters could be damaged too severely for even a good PCB to read. A damaged preamp or damaged disk platter would most certainly cause the click of death syndrome you've described. A hot swap might be able to recover some of the data in either case.

Are you sure the replacement PCB works? If you only purchased the board and didn't pull it from a working drive you would have to trace the power/data lines and check there are no breaks in the circuit. Repair would be very difficult, near impossible. Though a reflow could fix any dud connections.

Even though you have a close match it might not be a sufficient replacement. Minor firmware differences are enough for the disk not to spin up. The controller won't spin the platters if it doesn't get the necessary feedback from the internals.

If you intend on getting at least some of the data you might find this site helpful. It details the preamp issue I mentioned as well the PCB hot swap method.


The PCB is more than just a controller. The firmware is important, but also the drive contains information about the drive it is paired with, such as bad sectors.

The flash from one pcb would need to be copied over to the new one. If they were identical parts, the liklihood of this working is low. That they are different parts means the probability of success approaches zero.

I would imagine the pcb is fine, but it isn't telling the disk to spin up because the disk doesn't have the expected characteristics.

  • is copying the flash from one PCB to another a simple task, can you link to something that may help me do that? I would like to get some educational value out of this new PCB i just bought...
    – GiH
    Commented Oct 19, 2011 at 22:58
  • Some drive manufacturers release updates to their firmware. If this is the case with your disk, then they might have a firmware update tool that also allows downloading of the current firmware.
    – Paul
    Commented Oct 20, 2011 at 0:16

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