I have 4 Hard drives that have bad PCB’s, If I swap out HDD with a working board I can get them to spin. so I’m assuming a bios chip swap is all I need. Do I send you the damaged boards and you repair them, or how does it work?
We just sell PCB.
You can move the BIOS from your original PCB by using hot-air gun, then soldered it on the replacement board. Please refer: hard drive pcb firmware transfer . Or you can find an electronics repair shop help you.

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