Hello all,

We have a dead PCB and we have found a donor for it.

The problem is that the PAtient HD with DOnor PCB is detected, but unable to access user LBAs.

We are looking to swap the ROMs from the Patient to the Donor and we would like to confirm where the ROMs are.



Any input would be great.

Thank you,

I see you have removed the 5V TVS diode, but did you check the fuse ("s")? That may be the only problem.

Similar setup:

http://users.on.net/~fzabkar/HDD/0A90701/TVS_diodes_fuses.jpg

There also appears to be an e-fuse, but I would need a much clearer photo to help you. IMHO, your best approach would be to repair the patient PCB. An e-fuse can be bypassed with a wire link or solder blob, so a repair is likely to cost you nothing.

Moving ROMs involves some risk. Also, some PCBs are locked to the MCU. I don't know if yours is one of these.

https://ae04.alicdn.com/kf/S3f1e8da2b2b643d4952f17f6bc20fc6f0.png

_________________
A backup a day keeps DR away.

MP5098GDT, Monolithic Power, 12V/5V, Low IQ, Dual-Channel E-Fuse with Current Monitoring, marking BLB, TQFN-10:
https://www.monolithicpower.com/en/documentview/productdocument/index/version/2/document_type/Datasheet/lang/en/sku/MP5098GDT/document_id/10499/

GD25LH32D, GigaDevice, SPI flash, 32Mbit, 1.65V - 2.0V, SOP-8 / USON-8, WSON-8, WLCSP-8:
https://www.mouser.com/datasheet/2/870/GigaDevice_Product_Selection_Guide-1947349.pdf

IS25WP032D, ISSI, 32Mbit, SPI flash, 1.65V - 1.95V, 8-pin:
https://au.mouser.com/datasheet/2/198/25LP_WP032D-1090958.pdf


https://i.ebayimg.com/images/g/zzcAAOSwe4lkFCq6/s-l1600.jpg

_________________
A backup a day keeps DR away.

Does not look like anything has been removed from the PCB



In the photo, the damaged PCB is on top and the part PCB is on the bottom

Thank you for the information on the

I now see that the 5V TVS diode was not originally populated by WD. They must have saved all of 10 cents.

If the e-fuse is faulty, you can bridge the Vin and Vout pairs.

This thread has more info:

https://forum.hddguru.com/viewtopic.php?f=1&t=42330

Apparently the MCU needs to be transferred as well, not just the ROMs.

_________________
A backup a day keeps DR away.

Thanks for the additional Info there.

Seems me adding photos to the message needs approval

Can you measure the voltages which I have identified in that other thread?

Can you also identify the markings on the smaller ICs, ie the converters, e-fuse, load switch / MOSFET?

_________________
A backup a day keeps DR away.

Everything seems fine. The ROms are currently being moved to the donor Board.

BTW, the HD appears to work with the Donor PCB, but unable to access User Sectors.

Can you upload your ROM dumps? I have written a tool to parse these ROMs and test their checksums.

_________________
A backup a day keeps DR away.