Seagate 1TB 100536501 REV A PCB solder advice required

[ccfc1927]

My hard drive did not work when I connected power to it.
An IT technician friend opened up the external hard drive unit for me and discovered that part of it was burnt out. See attached image.
I searched for issues with this PCB and it seems a common problem, and most issues are resolved by by-passing the damaged circuitry with a wire solder. I have done basic soldering before, but have no circuit experience, especially concerning pcb's.
Could anyone tell me by looking at my damaged circuit board if I have any chance of salvaging. If so where would I need to solder?

Thanks for your time.

Attachments

Picture of my burnt pcb:100536501 REV A

[northwind]

I kindly disagree to your comment that this is a common issue. This looks like a major one, not like the "common TVS issues" you read in this forum.

IMHO, your best bet is to replace entire PCB.

[dmarques]

I would just to for relacement of the dagamed components if you know about electronics and be able to measure them.

Else, I would follow up northwind advice.

And in the end, it might have damaged also pre-amp, that is internal.

[fzabkar]

It's a common issue. The 12V TVS diode has shorted as a consequence of an overvoltage on the +12V supply. You can remove it with flush cutters.

Then clean up the charred area with a toothbrush and isopropyl alcohol (tape/video head cleaner). Measure the resistance between each of the diode's pads and the +12V and ground pins at the SATA power connector.

http://pinouts.ru/Power/sata-power_pinout.shtml

If one of the damaged components is an open inductor, then we can replace it with a wire link. It may be easier to solder to the diode's pads, though.

Let us know what you find.

[northwind]

OK let's see..

[fzabkar]

OK let's see..

I often encounter very similar damage at Seagate's forums. Plenty of end users have been able to repair their drives with a jumper wire. I've even shown one of your colleagues how to do it. ;-|

In fact it's trivial jobs like this that suggest to me that this forum is crying out for a simple Electronics 101 tutorial.

FYI, Seagate uses inductors in the supply line to each TVS diode, at least on some models. Unlike WD's zero-ohm resistors, these inductors are not fusible, so they burn up instead of going O/C gracefully. These inductors are usually on the +12V and +5V sides of the diode, but in the OP's case the charred components appear to be on the grounded side. That's why I asked for the resistance measurements.

[ccfc1927]

Thanks for the replies so far. I will clean up and try to get readings today.

[northwind]

I often encounter very similar damage at Seagate's forums. Plenty of end users have been able to repair their drives with a jumper wire.

I'm not going to rumble here about risks of such DIY, I've been through this a trillion times.

In fact it's trivial jobs like this that suggest to me that this forum is crying out for a simple Electronics 101 tutorial.

FYI, Seagate uses inductors in the supply line to each TVS diode, at least on some models. Unlike WD's zero-ohm resistors, these inductors are not fusible, so they burn up instead of going O/C gracefully. These inductors are usually on the +12V and +5V sides of the diode, but in the OP's case the charred components appear to be on the grounded side. That's why I asked for the resistance measurements.

What you say makes sense, no doubt, but I still insist that chances of internal damage (preamp) is high for this kind of pcb damage, based on experience. Lets hope (for OP's sake) that I'm wrong.

[fzabkar]

... I still insist that chances of internal damage (preamp) is high for this kind of pcb damage, based on experience. Lets hope (for OP's sake) that I'm wrong.

AISI, the overvoltage was limited to the +12V supply.

According to the L7250 (SMOOTH) datasheet, the preamp gets it positive supply from +5V. Its -5V supply is also derived from the +5V input, via an inverting buck converter. The +12V supply appears to drive the voice coil and spindle motor, whereas the +5V supply is used by the SMOOTH chip's digital logic.

Therefore ISTM that preamp damage would be unlikely, although not impossible.

[Amarbir[CDR-Labs]]

... I still insist that chances of internal damage (preamp) is high for this kind of pcb damage, based on experience. Lets hope (for OP's sake) that I'm wrong.

AISI, the overvoltage was limited to the +12V supply.

According to the L7250 (SMOOTH) datasheet, the preamp gets it positive supply from +5V. Its -5V supply is also derived from the +5V input, via an inverting buck converter. The +12V supply appears to drive the voice coil and spindle motor, whereas the +5V supply is used by the SMOOTH chip's digital logic.

Therefore ISTM that preamp damage would be unlikely, although not impossible.[/quote

Well,
I Have a question to ask you ,what do you do for a living ? .If you Cannot answer it here i will create a special thread for you in the other section .

[ccfc1927]

It has taken a while but here is what happened since I last posted:
I calculated how much it would cost to buy the equipment, but realised it may be similar price to find someone with circuit knowledge and equipment to try for me.
I got in touch with someone last Friday and highlighted this thread to them.
They attempted to fix on Monday and they rang to tell me it looked promising. I picked up yesterday and I am really pleased to say that the hard drive is now working and I have been able to back up all the family photos and videos that I should have backed up originally.

I am extremelly grateful to fzabkar for his unoubted knowledge in this particular area of hdd/pcb issues, as well as my IT friend and the electronics repair services I used.

Thankyou again fzabkar, it has cost me a relatively small amount to repair, compared to the amount I would have likely been charged by a data recovery service company.