Just for araifa info:

If you swap over the ROM from the patient PCB to the compatible donor PCB. Then cover the pre amp connections with a piece of card & then attach that to the patient hdd housing the drive should spin up - which is good, disconnect power & PCB, remove the card covering the pre amp connections & then re-attach the PCB. If it then doesnt spin up then pre amp is damaged & could have possibly have damaged your donor PCB, thats the risk you have to decide to take. If the later happens then sorry no DIY as the internal heads & pre amp will need to be swapped by a pro.

Loki

The OP has already determined that the preamp is not shorted. That was the purpose of the resistance tests.

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A backup a day keeps DR away.

NOT SHORTED doesn't mean IT WORKS.

Nevertheless if it is SHORTED it likely can fry a new PCB.