Need a judgement on repairability of hard drive after outage

[ChazZeromus]

A drive of mine has one of it's chips on the PCB melted with bubbles and the sort after an outage. I was wondering if there was anything to consider that would impede the repairability of it before I buy a new PCB for it. Like is it possible the motor could have been damaged etc?

[networks]

Posting a picture and details like make model of hard drive might get you more assistance with the very limited info provided thus far its justna stab in the dark. I dont get why people cant provide the very basics of info when posting just dont get it

[pcimage]

http://www.donordrives.com/blog/pcbswapguide

This might help

[ChazZeromus]

Posting a picture and details like make model of hard drive might get you more assistance with the very limited info provided thus far its justna stab in the dark. I dont get why people cant provide the very basics of info when posting just dont get it

Whoops, yeah my bad, my drive is a "Maxtor QuickView 6L160P0", I don't have any pictures on hand of my particular one but I do have an picture of the PCB that I'm wanting to buy. In the picture, the chip on the bottom left is the one that's bubbled up.

http://www.donordrives.com/blog/pcbswapguide

This might help

Thanks, I've googled around and I've been told the same requisite information. The hard disk does not spin and no activity can be heard, but I'm just wanting a second opinion.

Attachments

[labtech]

Is that PCB the drive's PCB or some random pic?

Motor is unlikely to have sustained damage. Other component on the HSA maybe.

A pcb swap is worth a shot as long as it is compatible on your drive.

[ChazZeromus]

Yeah it's a pic from an ebay vendor that sells the exact PCB that was fried, serial number on the circled area is the same and everything. What's an HSA?

[labtech]

Head stack assembly

[northwind]

Go ahead and swap the pcb.

[ChazZeromus]

Thanks for the input guys. I hope my data is still there. To elaborate more on what happened during the outage if it's any significant information, the first thing that was of noticeable damage was the PSU. After the outage, the computer turned off, and upon turning it back on the PSU sparked and smoked a bit, so obviously that wasn't usable anymore. As of the now, all the components affected are the PSU, motherboard and the hard disk. The motherboard has no sign of physical overvoltage other than the fact it doesn't turn on.

[fzabkar]

CR203 is the 12V TVS diode. Snip it out with flush cutters and hopefully you will be good to go. Just be aware that you will now have no overvoltage protection at that location, although there is a second 12V TVS diode above the SMOOTH motor controller chip. Therefore make sure your PSU is good.

See http://www.users.on.net/~fzabkar/HDD/TVS_diode_FAQ.html

[ChazZeromus]

Well that's good news but, there are holes where they're shouldn't be on the chip that says SMOOTH, which I think is the motor controller. I think that's another reason why it's not gonna work. I'm also reading that some drives may not startup even with a PCB replacement because a fried motor controller could also fry something in the disk assembly, is this possible for my maxtor?

Last edited by ChazZeromus on May 7th, 2012, 4:46, edited 1 time in total.

[BlackST]

Well that's good news but, there are holes where they're shouldn't be on the chip that says SMOOTH, I think that's another reason why it's not gonna work.

Oh.... then NO WONDER it's not working

[fzabkar]

Well that's good news but, there are holes where they're shouldn't be on the chip that says SMOOTH, which I think is the motor controller. I think that's another reason why it's not gonna work. I'm also reading that some drives may not startup even with a PCB replacement because a fried motor controller could also fry something in the disk assembly, is this possible for my maxtor?

The motor controller also controls the onboard DC-DC converters. If the SMOOTH chip dies in such a way that the chopper transistor in a DC-DC converter is driven on permanently, then the associated load may be damaged. IMHO, good practice in these cases would be to measure the load resistance on each of these internal supplies, particularly the preamp supplies.

[harddrivespecialist]

Easiest way to approach it is to find matching PCB and try it.

I can provide that PCB to you for $25.00, plus shipping.

[ChazZeromus]

The motor controller also controls the onboard DC-DC converters. If the SMOOTH chip dies in such a way that the chopper transistor in a DC-DC converter is driven on permanently, then the associated load may be damaged. IMHO, good practice in these cases would be to measure the load resistance on each of these internal supplies, particularly the preamp supplies.

I just don't know whether it's too risky to buy a new PCB replacement now, I just want to be sure. And doesn't measuring the preamp require opening the drive? That sounds like something I'd leave to a professional to do.

If I posted a detailed enough picture, will be it be enough to deduce whether a simple PCB replacement is viable?

[labtech]

Nobody can guarantee anything via a remote forum based analysis. You have received plenty of good advice. All DIY comes with some risk which DIY-ers have to shoulder.

Posting a picture of your PCB may tell more, so, yes, post it.

[ChazZeromus]

Alright another question, let's say the preamp is damaged and I buy the new PCB and I test it, is there a high probability that I will damage the new PCB? If not then I could take it to a professional along with the new PCB right?

[labtech]

Possible and yes

[fzabkar]

The overvoltage arrived via the +12V input. This supply powers the analogue section of the motor controller, ie the spindle motor and voice coil. The +5V supply powers the digital section and the DC-DC converters (according to the application circuit in the L7250 datasheet). Therefore, since the -5V for the preamp is derived from the +5V input, I would expect that the preamp would not be affected by an overvoltage on the +12V supply.

In any case, you can test for a shorted preamp by measuring the resistance between ground and the -5V test point (near the 1R5 coil at 10 o'clock to the SMOOTH IC).

[ChazZeromus]

That's very reassuring, thanks fzabkar! I think I'll take your word for it though.