It has taken a while to refocus on this and I got hold of another PC board this time (with PCB Sticker: 0J14451 DA4740D, Controller Chip: 88I9305-TLA2, PCB Revision: 0A90351 matches. but have a different motor controller chip R2A30027 instead of TLS2601).

I transferred the ROM chip from original board to this one and disk was tested with a PC. When I power the PC on, I can hear (with my ear on the disk) that disk motor/shaft starting to move, making noise about 8-10 times, then it stops making any sound. This happens every time when power on.

When I mounted the disk using a USB cable to the PC, windows disk manager shows an unknown disk. Trying to boot the machine with this gives a bios error missing boot disk.

What could be the possible issues now, I'm thinking following possibilities:

1. the doner PC board is defective - I assume this is the possibility than next two.

2. ROM chip is burnt - (I used a CH341 based USB programmer and able to successfully read the firmware from the ROM - so I believe this is OK?)

3. last time I used a PC board that was sent by a vendor with unmatched PCB sticker numbers (Posted: May 5th, 2018, 2:40), I used it for few minutes to test with my ROM chip, as vendor thoroughly recommended to use it. That time I heard similar sound but did not try it many times - I'm wondering if this attempt could have damaged the disk or the shaft moved to a wrong location? which require mechanical fixes?

Many Thanks,
-JS