Hi

Recently my WD80EB-28CGH2 drive (might be from an OG Xbox since it was password locked) suddenly died (PC froze and then the HDD started clicking).
At first I thought the platters or heads gave up so I didn't think much of it. Out of boredom I swapped in a PCB from a known good HDD of the same model and turns out, the HDD works just fine. I can read the data and write. Using the bad PCB on the known good drive results in same behavior.

I am thinking it might be the EPROM corruption since the drive with bad PCB mounted isn't detected in BIOS. The PCB markings are 2060-001100-004 REV. B

What are your thoughts on this?

Measure the voltages at Q6, U4 and the diode adjacent to the motor controller.

_________________
A backup a day keeps DR away.

Diode near the motor controller:
Cathode: 12.21V
Anode: 11.91V

Voltage rails on U4 (K4S161622E-TC60 SDRAM):
Vdd: 3.27V
Vddq: 3.27V

Couldn't find any component labled Q6, closest I could find was U6 (ST3L01 triple voltage regulator)
Pin 1,4: 0V (GND)
Pin 2: 3.27V
Pin 3: 5.12V
Pin 5: 7.97V
Pin 6: 12.21V
Pin 7: 2.28V

Voltage on Q4: (labled BA QU)
Pin 1: 1.94V
Pin 2/tab: 1.86V
Pin 3: 2.58V

Hope this helps

Sorry, I meant U6 and Q4.

Pin 7 of U6 should be 2.6V. You have 2.28V. Did you mean 2.58V?

I'm not sure, but I think Q4 may be the pass transistor in a 1.8V regulator, in which case it is OK.

2SB1132, PNP transistor, marking BA, Rohm, -32V, -1A, 0.2V VCE(sat), Q marking = 120-270 hfe:
http://www1.futureelectronics.com/doc/ROHM%20SEMICONDUCTOR/2SB1132T100Q.pdf

_________________
A backup a day keeps DR away.

My mistake, pin 7 of ST3L01 is 2.58V.
Forgot to mention the "BA QU" is SOT-23. Closest match I found is BCW60 which seems to be a NPN transistor.

It tests like PNP, and the package looks like SOT-89 --> 2SB1132.

https://www.lcsc.com/product-detail/C79635.html?s_z=n_2SB1132

_________________
A backup a day keeps DR away.

Yup, now I get it. It's a SOT-89, not SOT-23 (this type is angled at the bottom).

Measured the voltages on my known good drive (different PCB sticker, but base model the same) and they seem within spec of what I measured.
I do not know whether it is the IC which are bad or is it just EEPROM corruption. Any ideas?

I don't know. A bad "ROM" usually prevents the drive form attempting to spin up. The read channel logic would be in the Talon IC.

_________________
A backup a day keeps DR away.

Might be able to borrow a oscilloscope to check what I get on the talon IC, but I don't know if that'll be any usefull info.