I recently replaced my power supply, and apparently I did something wrong when connecting my HDDs.
I ended up with four fried disks. Hooray for poorly tagged modular power supplies.
I have three years worth of work on those disks and don't have any external backups, as I made the stupid mistake of backing up between the internal disks. I mean, what are the odds of four disks failing at once, right? Right...

Anyway, after removing the PCB boards, it seems to be the same chip that's been destroyed on all of them; the L7251 3.1. Should I simply try to replace these, and hope for the best? Any kind of help is appreciated.
All disks are WDs, by the way.

Bloody hell, I wonder what caused that... The only recommendation is to find a replacement PCB board and swap over the ROM chips. But what gets me is why the TS Diodes did not protect the boards in the first place and all of the Smooth chips are dead too.

The only sound advice is get the drive with the most data on it, then take it to a good DR company who then could do the work for you. If its just the PCB board friend, it should not cost much, but if the preamp and other internal stuff died, then it might cost more. Since the drives can't be powered, damage should be minimal inside the drive and easy to recover.

The thing is, it seems only the Smooth chips have been destroyed. Isn't it possible to replace them?

I would be going to a DR company.

I guess you saw this post:
http://forum.hddguru.com/viewtopic.php?f=1&t=26808

If you have a look at the datasheet fzabkar posted it might tell you if the chip is just a passive component(my term for "don't have no ROM code you gotta change") I don't know anything about them myself.

boy, you were pretty unlucky there..

The problem is the contacts look all burned, but what concerns me is how did a high current pass through all the protection devices and fry the chip. Chances are that if an over current fried the smooth chips, then the larger controller and other components would have unseeable damage too. A new PCB board would be a safe option.

Hi, you can't simply just switch the Smooth chip...as you probably have damage in more circuits on the board.
And more worrying is that, if the short-circuit was that powerful you most likely have bad preamps inside the drive as well.

I can see you live in Norway, if you want you can send them over to Sweden and I'll take a look at them.
If so, send me a PM.

Best Regards/ Bosse

_________________
Rescue IT Datarecovery service Sweden
Rescue IT Dataräddning Göteborg AB
http://www.rescue-it.se

I have a cousin who works at a computer repair shop. He said he could get new PCBs and switch the rom chips. If that doesn't work, I might take you up on your offer.

I see also a lot of oxidation on pcb on the bottom right, this could caused also malfunction on head that could caused bad sectors appearing.
If you will be able to fix drives after finding donator pcb and doing the rom transfer, you also need to check if there are bad sectors, i bet there are at least some pending sectors on the drive where it was mounted the pcb in the bottom right of the pic, very likely also on the drive of pcb on the top pic.

Let me guess...
you changed the power supply because u saw that hard drive were not working good
but u did something wrong with power supply and situation now is worse

_________________
My firmware database:
https://mega.nz/folder/O01DkBRI

You're welcome.

_________________
Rescue IT Datarecovery service Sweden
Rescue IT Dataräddning Göteborg AB
http://www.rescue-it.se

No, my computer stopped working because the PSU died, and the computer didn't get any power. I tested it, and made sure that was the problem.
I bought a new one, connected it and when I started the computer, it smelled like burnt plastic.
I've double checked the connections, and I honestly don't know what the problem is. I've built my own computers since 1999, and I've never had this happen before.

My PC recently had a power supply burn up and start smelling. After changing the PSU the PC would take a long time before it got into POST. It would eventually go into POST and run fine. A few weeks later it just turned itself off. I took out the motherboard and noticed the capicitors had fried/blown on the motherboard. They had burn marks on top and where slightly raised/bumped. Maybe that is your prob too FWIW.

And thats probably when the drives died as well...

_________________
Rescue IT Datarecovery service Sweden
Rescue IT Dataräddning Göteborg AB
http://www.rescue-it.se

Measure the resistance of TVS diodes D3 and D4, and zero-ohm resistors R67 and R64.

I expect that D3 will be shorted and R67 open circuit. If so, then this would point to an overvoltage (or reverse voltage) on the +5V supply. The damge to the SMOOTH chips is consistent with damage to the Vcore and Vneg supplies. The latter powers the preamp, as does the +5V supply. Therefore I would expect that all 3 preamps may be dead.

As for why the TVS diodes didn't protect the drive, it appears to be due to some stupid design decision. WD's zero-ohm resistors appear to protect the external PSU from a shorted TVS diode rather than protecting the drive from a faulty PSU.

_________________
A backup a day keeps DR away.

spokk: I doubt it. There was no smell when the PSU died.

fzabkar: Will do so tomorrow.

I would guess that your motherboard, CD drive and other components on that computer would be damaged too. Might need a new computer and start blaming the power supply manufacturer or shop for the damage. I guess a lot more voltage went down the 5V Supply rail then it should have been. Probably 12V or 24v.

Shane

I'm back.

I replaced the PCB board on one of the drives and had the ROM chip moved.

The drive in question now spins up, but starts to make a clicking noise. I've listened to the various clicking samples, but couldn't find one that matched. It's basically sounds like squeaking followed by a clunk, which repeats about once every 1.5 seconds or so.

Do I give up, or is there still hope without sending it in for repairs? Does this indicate the preamp is intact?

The drive is a WD2001FASS 00W2B0, and the PCB number is 2060-771624-003 REV A.