PCB revision question on ST2000DM001

[spakhnyuk]

Hello everyone,

I have a 2TB Seagate Barracuda ST2000DM001 in for data recovery that has a bad PCB.
I found the same model number donor drive, but the revision on the PCB is different.

The drive I'm trying to recover data from uses a 100645422 REV A board.
The donor drive uses a 100687658 REV C.

When I swap over the ROM chip to the donor board, the drive powers on, spins up, but does not get detected by the DDI.

Any suggestions on a workaround or do I absolutely have to have the correct board revision?
Any tips on troubleshooting the bad PCB would be appreciated as well.

Thanks!

Attachments

[fzabkar]

Measure the voltages at the coils (R47, R47, 1R0). Also measure the voltages at the 5V and 12V TVS diodes.

[spakhnyuk]

Measure the voltages at the coils (R47, R47, 1R0). Also measure the voltages at the 5V and 12V TVS diodes.

Voltage at the TVS diodes is 5.12V and 12.75V (one that's near the edge)

R47 (further away from ROM chip) is 1.8V
R47 (close to ROM chip) is 0.95V
1R0 is 1.0V

[fzabkar]

Those voltages look OK (Vio = 1.8V, Vcore1 = 0.95V, Vcore2 = 1.0V).

There are two additional supplies. One is the negative supply for the preamp (1R2 coil and IC), while the other is generated by the TI 6855A IC near the HDA contacts.

Is there any output from the terminal port?

Attachments

Vio_Vcore.jpg (128.02 KiB) Viewed 5975 times

6855A.jpg (73.79 KiB) Viewed 5975 times