Have you read the CAUTION messages regarding risks of DIY on this board?
Do you accept the risk of DIY? This risk means that you can damage the drive beyond ANY repair (to a point not even a very high skilled pro could help you) or make recovery *x times more expensive.
If you do accept, read on. You have been warned. If you give this to a pro, and assuming problem only with pcb, then it wouldn't be too costly. Think again, then read on.
If you accept risks of DIY, then this is pretty straightforward.
Find the number printed on the pcb, namely 2060-xxxxxx-xxx rev x. (should be 2060-001292-xxx if i'm not mistaken).
Then order a new pcb with the same board number.
Transfer chip u12 from old pcb to new and fire up your hdd.
If you're lucky, and assuming you've done everything right, all files should be accessible.
If you're not lucky, then preamp is dead, and it is game over for diy. And in that case, these drives suffer from head alignment problem, so it should be fun for the pro you will send to

Good luck.