Freaking WD4000AAKS is toasted.. pc wont even boot when plug

[rizla420]

Backstory:
Last night i was watching tv, then decided to go do stuff on my comp. My monitors were in hibernation mode, i jiggled the mouse, never woke up. Turns out the computer was off. Pressed the power button, no response. Figured the power supply went bad (common), grabbed one from another PC i had and unplugged the old power supply and connected everything back up identically. Clicked the power button, nothing. I knew the power supply was good.

Next step, i unplug all the peripherals to test one at time. I realized that whenever i plugged my primary drive, the computer would start. I tried to be sneaky and start the computer THEN plug the drive in. Guess what.. once i plugged it in, the whole computer shut down. So this drive was causing a short somehow in the power supply. Also, the drive never spun up. Once i plug power, the system crashed, but the drive never spins.

Mind you, when i was able to successfully get the power and fan to turn on, but no bios info was being displayed on screen.

Advice:

Whats my course of action? I've been reading forums all day long at work (not working) and have read about the issue with the newer HD SATA drives having custom code written for each drive. Therefore a PCB swap wont work. My question is, before saying it wont work has anyone successfully swapped a fully matching PCB on the new WD drives?

If I do go ahead and swap it and i fail, would it further damage the drive?

I've also been looking at Data Recovery specialists in my area. How do you distinguish a good shop from a bad one and what type of costs are we looking at. 500-2k?

Yes yes, i know its all about how much you data is worth to you..

[rizla420]

BTW, i'll try to get pics of it when i get home. Nothing looks out of the ordinary, but then again i was troubleshooting from 12:30-2...

[HDD Spaz]

You could end up killing the other pcb, and im 95% sure it wont be compat with the failed one so dont waste your time. What area are you in, maybe we could recommend someone off the forum.

[rizla420]

Alright, so i read on another thread someone having a very similar issue as mine, basically the comp wouldnt start with the drive plugged in. According to him and others it was the TVS (not sure what it is, or hwere it is). They said if you take it out theres a good chance i could get it to boot. Also, in order to check to see if the TVS is whats blown, do i have to remove the PCB to flip it over or is it visible in an assembled drive?

Anyone else have some preliminary troubleshooting i can do?

I live in Boston, so if anyone knows of some good places around here, it would be helpful.

[harddrivespecialist]

I am in Rhode Island, and will be able to help you

[rizla420]

Just got home, popped the pcb off and took a very close look at all the chips. Nothing sticks out particularly that looks burnt out. I do notice some tarnished spots that probably got hot, but thats the extent of it.

I've asked this before, but how do you locate the TVS diode? Is there some sort of marking I should be looking for? Shape? Its a 400GB Western Digital Caviar SE 16MB. I took some pics with my iphone, but it def isnt sharp enough for someone to point out.

[rizla420]

Trying to upload images:

[rizla420]

Here are the rest, hopefully the resolution is clear enough. The only thing i see is tarnishy color on some of the component... hopefully this helps with the diagnosis..

[pcimage]

The TVS's are at D3 & D4, top right.

May be worth a shot to remove them.

But if that don't work, then put them back (The right way round, thay are polarised) otherwise your PCB will have no protection against any possible spikes.

[dick]

If you have or can get hold of a multimeter you could test each of the tvs's. You would be able to see if either is showing a short circuit before removing either of them.

In a usual scenario one will go short and stop the pc from starting. Remove the shorted tvs and then try to power the drive once more.

Before attempting to power the drive it would also be good pactice to use the multimeter on the tvs pads after removing it to confirm the short circuit has been rectified.

[rizla420]

So, i was testing the continuity and I think i found the culprit. I'm using a WD500GB drive that has a virtually identical PCB to see what the differences are. I circled in red the part that currently has continuity on the busted drive. One the good drive i get no continuity. All the other little diodes have the same continuity as on the good drive. This one part is the odd man out. Is this the culprit that shorted? If it shorted wouldnt it not have continuity? Or since its supposed to have continuity the short is whats causing it to pass the current through. Should i be brave and lightly solder it off?

Take a looksie:

[drc]

If you google TB13A (the markings on that component) the first hit is

wd5000aaks-00tma0-firmware-2061-701477-900-04p-t9998.html

[rizla420]

If you google TB13A (the markings on that component) the first hit is

wd5000aaks-00tma0-firmware-2061-701477-900-04p-t9998.html

I know i read his post already, thats what gave me some comfort in thinking that it was the TVS and low and behold it was.. i'm just debating whether i should give it a try and possibly fuck things up or "take it to an expert" i'm probably going to take it to an expert for an eval and see what their conclusion is.

[ultimax]

Hey I was wondering if you got your drive fixed? If so, how'd you do it?

The exact same thing has just happened to my Seagate Barracuda 80gb. Same symptoms, probably same cause.

The drive's now at a data recovery company. The evaluation's free, so I'm sitting pretty waiting for a quotation. It's $200 minimum, and surfing local forums the actual figure can multiply by a factor of 10!