Seagate 320GB ST3320820A - PCB swap?

[Vulcan]

I have followed the instructions here, and checked the 3 TVSs with a multimeter, but it seems that none are shorted.

There are not 3 TVS diodes, so your comment doesn't make sense, unfortunately

Therefore please explain your exact measurement results and what you did, attach a close-up photo of your drive's PCB (component side up) to your posting, and you may get some further advice / suggestions.

Since your data has real value to you, are you really sure that you want to be trying DIY recovery and hence incurring the associated risks? Are you familiar with ESD precautions? Anyway, it's your data, so it's your choice about taking the risks...

[TaraM]

Hi there. thanks for your quick response.

I thought there were 3 TVSs because of the last post by the original poster. I thought that the component at the opposite corner of the board (next to the 3 on the bar code label in my pic) was also a TVS. I have only checked the current in either direction through these 3 components, so I hope I have not done any further damage.

Apologies for the confusion, but I checked the TVSs again with a different multimeter, as my better half told me the one I was using was broken. so now I get 0.002 when I short. The display shows 1 when there is no contact.

the TVS running top to bottom (the corner most one) gives 0.626 in one direction, 1 in the other.
the other TVS, running left to right shows 0.174 in one direction, 1.578 in the other. Could this one be broken?

I really appreciate the help.

I have considered paying for recovery, but I heard it is expensive. I was going to read the advice posted, and then decide.

T

Attachments

[fzabkar]

Neither of your TVS diodes are shorted. The third diode near the barcode is a Schottky rectifier and is part of a DC-DC converter.

I believe your most expedient solution may be to swap the board and, if necessary, transfer the 8-pin "SST" flash memory chip near the jumper block to your donor PCB.

Of course I'm assuming that your PCB really is faulty. Does the drive spin up?

If you decide to replace your PCB, the following supplier includes a firmware transfer for US$10:
http://www.onepcbsolution.com/st3320820 ... -4196.html

[TaraM]

Thanks for the reply.

When I switch it on, the light on the external caddy comes on, the drive starts to spin up, but there is a clicking noise and it feeld like it hasn't finished spinning up. I thought that it was because the drive wasn't getting enough power, but perhaps there is another reason.

Thanks for the link to the PCB supplier, They are out of stock at the moment. I hope I can find it somewhere as the drive is quite old at this stage.

Thanks again

T

[sdmoore]

Hi, I know this is an old thread but just wanted to add my recommendation of "PCB Solution" for supplying a replacment PCB for this drive.

My sister managed to plug the wrong power supply into her Maxtor 320GB external drive which then wouldn't power up. She was using this as her backup device but hadn't grasped that a backup should be a copy of your files and not the 'only' copy of your files ... she was deleting her backed up files from her laptop after transferring them to it! Sheesh!!

So I opened it up and found 12V TVS on the Seagate ST3320820A had shorted. I removed it but that still didin't fix it as my Sharkoon Combo drive port was still reporting over current. So I saw the above link and thought $40 sounded it was worth a shot before contemplating a recovery firm.

Anyway, I ordered one of these http://www.onepcbsolution.com/st3320620 ... 53-tk.html and after about 4 working days it arrived here in the UK, I swapped the board in and, bingo, drive working and all files intact! I now have one very happy sister who now has a better understanding of backups

Cheers,
Scott

[rickatnight11]

I just registered to say thank, everyone! My sister's husband did the same as everyone else in this thread and hooked a laptop power cable to her external Seagate drive. Tons of priceless wedding and birth photos seemingly gone (I know, I know, she's been sternly admonished.) Heading down the PCB-swap route I immediately came across this thread on Google. My buddie's multimeter confirmed a short in one of the diodes. Popped that bad boy off and backing the data up as I type this? Ya'll rock!