Hi, I had a Seagate Barracuda ST3500820AS HDD. The HDD now does not work and when plugged it is not recognized by the BIOS or Windows so I hope it's a PCB failure.
As such I am looking for an identical drive so l can try swapping out the PCB in the hopes that I can get the drive working to extract the data.
The HDD was a Seagate Barracuda ST3500820AS (8MB cahce) FW: SD81, but all l can find to buy are ST3500320AS (32MB cache).
Was wondering if anyone knew if is it possible to swap the PCB betwen these two models or any other 7200.11 model.

Thanks in advance (and sorry for the bad english),
Massimo

Please do read following post:
diy-what-the-big-deal-t12671.html#p83231

Besides that a pcb allone - without special knowledge and tools will not help

Contact a local DR company - or a very good one out of this forum
would recommend BlackST he is in Italy

+++

Maybe it's the wrong forum... but I'm not sure I don't care a lot the data inside the hdd all I want is to teach myself and experiment with an already dead hdd.
If this forum is only to sell DR Pro services... I'm in the wrong place sorry.

Allora buoni esperimenti e buona fortuna. P.S. non e' morto, e' mezzo morto. E' diverso !

Then enjoy tinkering and good luck. P.S. it's not dead, it's half dead. It's different !

op: your hard drive is known for firmware failure. Your first step is to search the forum on how to build a seagate terminal adapter. With this you can get better diagnostics. Then if your lucky and have the common firmware bug you can search this forum for the relevant firmware solution.

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Zero Alpha: zeroalpha.com.au
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haha yer. But a terminal log will do the op a lot of favours.

_________________
Zero Alpha: zeroalpha.com.au
Find Cheap Donor Drives App: https://www.zeroalpha.com.au/donor-drive-app Updated February 2026