WRONG VOLTAGE - WDC 2060-810011-001 P1

[gps31]

Due to Wrong Power Supply external WDC not working. In this

HDD: WD40EDAZ With PCB 2060-810011-001 P1

12V Fuse opened.

I can not find TVS Diode in this PCB. After Jumper HDD is not Power up.

I have no other PCB So trying to fix this PCB.

How to Trace Further? Pls HELP

[gps31]

The marked IC Named "iayuk" what is this IC and its Function?

[Mikippp]

Hi,
The G512 is electronic fuse.
https://www.st.com/resource/en/datasheet/stef512gr.pdf

Mikippp

Attachments

[fzabkar]

Si3456DDV, Vishay Siliconix, N-Ch MOSFET, 30V, 6.3A, 6-TSOP, marking AYxxx:
https://www.vishay.com/docs/69075/si3456dd.pdf

You can bypass the e-fuse (G512) if there are no other faults. I can help you test for shorts, if you want.

[fzabkar]

These are the bypass points.

[gps31]

Tried this bypass but NO SPIN UP

[fzabkar]

Did you measure the input and output voltages? Was the e-fuse bad?

Did you also bridge the open fuse on the 12V input?

[gps31]

Red Colored - NO Continuity
Yellow " - Shows Continuity

All these Three IC marked as "936 IL2"

[fzabkar]

I don't understand why you are focussing on 3 diodes. I would think that the first obvious thing to do would be to tests for shorts to ground at the 12V input and output pins of the e-fuse. See pins 1 and 8 on page 3 of the datasheet.

[gps31]

no short in 12v rail.

Bypassed e-fuse and jumpered 12v fuse. HDD is not spinning

[fzabkar]

Those diodes appear to be part of a power loss data protection circuit.

STPS1L20M, STMicroelectronics, low power drop Schottky rectifier, 1A, 20V, 0.37 Vf, marking 1L2, DO216-AA:
https://www.st.com/resource/en/datasheet/stps1l20m.pdf

You should see a +5V backup voltage on the bank of capacitors to the left of the Si3456DDV MOSFET.

There are several inductors in the vicinity of the motor controller. These will be the low voltage supplies for the controller, SDRAM and ROMs. I would measure the voltages at these inductors. That would tell you if the motor controller is working, at least partially.

I suspect that two of the "ROMs" would contain cached write data while the third would be the actual firmware ROM. The drive would save the SDRAM data to the two ROM caches in the event of power loss. This seems to be common practice in SMR drives.

IS25WD040, ISSI, Serial Flash Memory, 80 MHz Dual-Output SPI Bus, 512K x 8 (4 Mbit), 1.65V – 1.95V, 8-pin:
http://www.issi.com/WW/pdf/25WD020-040.pdf

Please note that much of this is just conjecture, so you may find that I've misinterpreted some aspects of this PCB.

Attachments

ROMs.jpg (119.1 KiB) Viewed 29075 times

[gps31]

[Lardman]

Please note that much of this is just conjecture, so you may find that I've misinterpreted some aspects of this PCB.

That's really helpful, thanks for taking the time.

[fzabkar]

The motor controller appears to be producing all the correct voltages -- +1.5V, +1.8V, -3V, +1.11V, +1.0V.

The negative supply for the preamp now appears to be -3V rather than -5V as in earlier designs. Also, the freewheeling diode is now inside the motor controller, so this regulator is now harder to visually distinguish from the other buck converters.

Sorry, but I can't see what is wrong with this PCB. Could it be configured to power up in standby (PUIS)? Is the PCB detected by your tool or your software?

Is the "+5V backup" supply present?

[fzabkar]

This is a wild guess, but I'm wondering whether this is the supply for the piezoactuator on the headstack.

Va and Vb would be the positive and negative voltages for the piezotransducer. Would it be worth checking?

Attachments

[fzabkar]

I'm thinking that the open 12V fuse points to a failure in the 12V circuitry -- e-fuse, backup circuit, motor controller, spindle motor, VCM, piezoactuator supply.

IIUC, this is a locked PCB, so it needs to be repaired.

In my experience in the user forums, external WD drives that have experienced an overvoltage with the wrong AC adapter typically sustain damage to the 12V TVS diode. The adapter's own current limit is enough to prevent damage to other components, including the zero-ohm resistor. Therefore I am surprised that the overvoltage has apparently punched through the e-fuse which should be more robust than a TVS diode.

[gps31]

Today I got Same PCB 2060-810011-001 P1 from WD Purple 4TB

that PCB has no e-fuse have TVS Diode having only Single Flash Chip

Tried this PCB with this HDD but No SPIN

[fzabkar]

Purple drives are often used in DVRs, and these are often configured for PUIS.

Did you first try the donor PCB with its own ROM?

Did you measure the motor windings?

Could it be a stiction case?

Just to satisfy my curiosity, could you please measure the Va and Vb voltages? I suspect that Va = -Vb.

[jono-ats]

I suspect that two of the "ROMs" would contain cached write data while the third would be the actual firmware ROM. The drive would save the SDRAM data to the two ROM caches in the event of power loss. This seems to be common practice in SMR drives.

I don't think the 2 other EEPROMS are for caching data.

[fzabkar]

Could we see a ROM dump?