Bad TVS diodes on Seagate hard drive.

[4tified]

I have what I beleive to be two bad TVS diodes on my Seagate LP 2TB hard drive. I plugged in the wrong power supply to my RAID, and well, you can imagine what happened. The drive no longer spins up. I've had this issue before, and sent my drive off to Seagate to be replaced.

THIS time, I would like to get my data off first. I've heard that you can take the diodes out of circuit temporarily to bypass this (I know it's dangerous to the drive).

On the other hand, I have a crap load of "donor" drives (ie: Seagate 40GB 7200.7) that I can desolder the TVS diodes off of, are they genreally the same values? The numbers on the modules themselves don't give me any info and googles searches turn up absolutley nothing.

I would post pics, but there is no obvious damage besides the smell.

Any help is appreciated.

[MixMasta]

Re: Bad TVS diodes on Seagate hard drive.

Can't you swap the circuit board with a working Seagate LP 2TB. Certainly you have more than one if it's a raid? You want to make sure the date codes are close so they will have the same firmware, etc.

[4tified]

Re: Bad TVS diodes on Seagate hard drive.

Can't you swap the circuit board with a working Seagate LP 2TB. Certainly you have more than one if it's a raid? You want to make sure the date codes are close so they will have the same firmware, etc.

I don't have a second drive. The drive was in the RAID enclosure, ready for a second drive to be added when I could afford it. 2ndly, I don't see any spare PCB boards on ebay or the like to use for the one currently on the drive.

[kc8adu]

Re: Bad TVS diodes on Seagate hard drive.

no you cannot swap boards unless it is an EXACT! match and you transfer the eeprom containing the adaptives.
desolder the tvs and use a good power supply this time.
and pray they clamped in time to prevent damage to things like the preamps.

[4tified]

Re: Bad TVS diodes on Seagate hard drive.

no you cannot swap boards unless it is an EXACT! match and you transfer the eeprom containing the adaptives.
desolder the tvs and use a good power supply this time.
and pray they clamped in time to prevent damage to things like the preamps.

Lol, me too. Gonna give it a shot. First to measure the 12v TVS to ensure that is indeed the issue.

[4tified]

Re: Bad TVS diodes on Seagate hard drive.

Bypassed both TVS diodes on the hard drive itself, drive still will not power up.

Guess I am out of luck unless I can find and exact match PCB, and chances are I won't find it since this drive is so new.

I am open to suggestions, but my thought is that I'm screwed for now.

[MixMasta]

Re: Bad TVS diodes on Seagate hard drive.

I've recovered data from IBM Deathstars and a couple of Western Digitals this way. When hunting for these used drives on ebay, you want the same country of origin and a date of manufacture as close as possible to the broken one. I'll add, I was able to get data off a western digital hard drive one time using the circuit board of a similar model but still not exactly the same hard drive (16megs vs 8 meg drives).

[kc8adu]

Re: Bad TVS diodes on Seagate hard drive.

Bypassed both TVS diodes on the hard drive itself, drive still will not power up.

Guess I am out of luck unless I can find and exact match PCB, and chances are I won't find it since this drive is so new.

I am open to suggestions, but my thought is that I'm screwed for now.

bypassed?with what?
just remove them.

[4tified]

Re: Bad TVS diodes on Seagate hard drive.

bypassed?with what?
just remove them.

Sorry, that's what I meant. I removed one lead per diode, the drive did not spin back up. Instead of proceeding further, I resoldered the leads on, then went ahead and requested a replacement from Seagate. I'll just swap the logic boards to recover the last few weeks of data and zero the drive before sending the bad drive back.

Thanks for the help anyway guys!

[Agent24]

Re: Bad TVS diodes on Seagate hard drive.

Let us know how you get on with it...

[riotpack]

Re: Bad TVS diodes on Seagate hard drive.

I had a 1TB Seagate and I accidentally it (LoL) by switching the 5V and 12V rails. I grabbed an old Maxtor 40GB sitting on my desk and unsoldered the SMD diode and soldered on the Seagate and away it went. I used it for a further 3 months and sold it.