Seagate PCB picture - is it faulty?

[Nuttz25]

Can anyone tell me if this board should be faulty? I got it off of ebay to replace an obviously fried board ( 3 of the whatyamacallits... diodes? next to the power were fried) The two scorch looking marks on the connections to the hard drive are making me wonder if I shouldn't try and get another board because I was sold a faulty one... Or got the wrong one, I only matched model numbers. Or, perhaps the damage to the hard drive is more severe than I think... Here is a picture of the replacement I purchased.

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[pcimage]

1. They are not "scorch marks" just normal corrosion.
2. What was the problem with the original drive?
3. Why did you think that a new pcb would fix your issue?

[fzabkar]

It sounds like the original board may be easily repairable. Probably just a shorted diode and a couple of burnt inductors or zero-ohm fuses. If you have acces to a soldering iron, a DIY repair should cost you nothing.

Could we see a photo of the damage?

[pcimage]

It sounds like the original board may be easily repairable. Probably just a shorted diode and a couple of burnt inductors or zero-ohm fuses. If you have acces to a soldering iron, a DIY repair should cost you nothing.

Could we see a photo of the damage?

Yes, or swap the "ROM" chip (8 legged chip bottom right) to the new PCB.

Usual DIY disclaimers....

[fzabkar]

TVS Diode FAQ:
http://www.users.on.net/~fzabkar/HDD/TVS_diode_FAQ.html

Photos of relevant components:
http://www.users.on.net/~fzabkar/HDD/ST ... 2V_TVS.jpg
http://www.users.on.net/~fzabkar/HDD/ST ... 5V_TVS.jpg
http://www.users.on.net/~fzabkar/HDD/ST ... uctors.jpg

Plenty of similar cases at Seagate's forum.

[pcimage]

TVS Diode FAQ:
http://www.users.on.net/~fzabkar/HDD/TVS_diode_FAQ.html

Photos of relevant components:
http://www.users.on.net/~fzabkar/HDD/ST ... 2V_TVS.jpg
http://www.users.on.net/~fzabkar/HDD/ST ... 5V_TVS.jpg
http://www.users.on.net/~fzabkar/HDD/ST ... uctors.jpg

Plenty of similar cases at Seagate's forum.

He said "3 components fried" which suggests a little more than TVS, hence why I suggested the ROM transfer, especially as he has a donor PCB.

[fzabkar]

1 diode plus 2 inductors = 3 components

Seen it plenty of times ...

http://forums.seagate.com/t5/Barracuda- ... ata_drives

[pcimage]

I was only trying to offer an easier and potentially more likely solution to the OP's problem (as he'd already bought a donor PCB), but clearly you know better than me.

I shan't bother in future as I hadn't realised it was a competition.

[fzabkar]

Your solution involves swapping the EEPROM. Mine involves flowing a blob of solder over an inductor and snipping a diode. I can't see how your approach is easier than mine.

If you think this job is difficult, I can show you numerous success stories in other forums, by complete novices.

As for your final comment, I hadn't realised it was a competition, either. I was just offering tried and tested advice. In fact I give the same advice to your colleagues, privately.

[fzabkar]

I was only trying to offer an easier and potentially more likely solution to the OP's problem (as he'd already bought a donor PCB), but clearly you know better than me.

Typical Seagate TVS protection

Code:

+V o-------------------|----o
                       |
                      TVS
                       |
Gnd o------------------|----o

Seagate board with inductors or zero-ohm resistors

Code:

         |-- L1 --|
+V o-----|        |----|----o
         |-- L2 --|    |
                      TVS
                       |
Gnd o------------------|----o

If the OP's board had been of the first type, then the advice would have been to snip the TVS diode.

Now that we have a board which is only marginally different, your advice is to swap the EEPROM. Why?

[mr_spokk]

Your solution involves swapping the EEPROM. Mine involves flowing a blob of solder over an inductor and snipping a diode. I can't see how your approach is easier than mine.

If you think this job is difficult, I can show you numerous success stories in other forums, by complete novices.

As for your final comment, I hadn't realised it was a competition, either. I was just offering tried and tested advice. In fact I give the same advice to your colleagues, privately.

PcImage advice is better, what IF there are more damage to the board...then you're going to blow the preamp.
Are YOU willing to cover that clients cost...don't think so!
Better to be safe, than sorry...

[Nuttz25]

I apologize for taking so long to get back, life issues. here is a picture of the original board.

Attachments

[Nuttz25]

So is my best bet to switch the ROM chip on to the new board?

[fzabkar]

IMO the safest thing for you to do would be to replace the burnt components with wire links, and remove the 5V TVS diode with flush cutters. If you damage the EEPROM, then the costs of data recovery will skyrocket.

You can make wire links out of the ends of a resistor leg. Clean up the area with a toothbrush and isopropyl alcohol (audio/video head cleaner).

[sathyan]

You can fix the old board if you can identify the burnt inductor and fuse ,and replace/fix them,(use the new PCB for reference) as well as check the TVS.

Or you can switch the ROM to the new board, if you are confident of doing that easily.

[Nuttz25]

First off, thanks for all of the input everyone! I ended up finding out that I (not a huge surprise) knew a professional electronics guy who had soldering in his job description... lucky. He was more than happy to jump the inductors with blobs of solder. My motherboard informed me that there was still a short in the system as it powered on and directly back off, and back on every 30 sec. or so testing.

I assumed the problem was the pcb that had been blobbed with solder, so I personally removed the original ROM chip and placed it on the donor board using a modified heat gun. Normal heat gun, modified tip using a nozzle attachment from an air compressor (typically used to blow dry parts covered in "lubricant/preservative"), attached to a flat washer... attached to some galvanized conduit that was dremel'ed down to the appropriate size to fit into the heat gun's nozzle. When I say attached, I mean there was some "metal" epoxy laying around.

Sidenote: Weak link was the epoxy, as directly after completing a test run, followed by the actual operation it fell off. 75 seconds of use. Fell the f off. What can I say, the distribution chain wanted $70 for the tips that would fit the heat gun, we made something similar with spare parts.

TLDR:

Switching a ROM chip on a similar board proved effective after frying 3 inductors.

Special thanks goes out to fzabkar!

[thatdellguy2]

Special thanks goes out to fzabkar!

Fzabkar's solder blob advice could have fried your preamp and cost you a lot more. No professional is going to repair a circuit board by using this method. Fzabkar's advice is 100% wrong and you got lucky...