WD PCB Replacement

1. PCB Replacement – I connected my WD6400AAKS Caviar Blue to a USB adapter, a smoke started coming out, it got extremely hot at the power connector. Looks like The PCB has a short. If I buy a replacement board, what are the requirements? Does it have to have the same exact model, DCM, LBA, etc? Please advise. Your response will be greatly appreciated. Many THX.

2. Western Digital WD500AAKS PCB Repair – Have an external hard drive, mdl WD5000AAKS-00TMA0 It ceased working one day, completely, no power. The PCB was burnt out, highly scorched in places so i changed it (an disposed of the broken one)
The new PCB was from exactly the same model, manufactured at a similar date. The drive now spins up and runs but unfortunately i can’t get any information from it. Cant get it to detect mounted in a PC, through the external carriage it detects the disk but doesnt recognize the size. Through Western Digital diagnosis the disk is detected but again no repair is possible, no size detected etc. If i boot up in something like disk part no detection occurs.
I’m all out of ideas and changing disk heads is a last last last resort. Can someone give me some pointers? does the PCB have a firmware with it as when i boot up another disk in WD Diagnosis model number, serial number etc is displayed.

3. Quick question about a certain WD PCB – Ive found a PCB replacement for my WD but i dont really know about the last numbers for example my model is Western Digital 80GB WD800JB-00JJC0, 2061-701292-A00 AP
but the one i found is Western Digital 80GB WD800JB-00JJC0, 2061-701292-A00 BD and also the one i have PWB 2060-701292-000 REV A but the one i found has PWB 2060-701292-002 REV A. I was wondering will that BD vs AP mean a big difference and on the PWB section will that 0 vs the 2 at the end make a difference?

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