I have non-working 3TB HDD, and I never probed anything digital like that before. I think it has a big jtag buss/pads. So far I found which chip is the motor controller, and ram, on the net, but I know this is all mission impossible. I should buy a replacement PCB
It has some corrorded pads, that I've read people re-tinned and got results, so I'll do that.
How often does a discrete part like resistor, cap, or inductor fail ? VS a chip goes bad ?
There's only 5 main chips, 2-3 voltage/current controller types, and I don't see any smd transistors, just R,C,L and a few diodes.