Need help with locating fuse on wd green hdd pcb

[Prelektro]

Hi,

My pc had electrical failure years ago and as a result my mobo and hdd got burned. Even though i got lots of old pictures, files etc. on this hdd i had left it on my shelf for years cause i thought it needed professional help (maybe it still does i'm not sure). Than, lately i decided to take another look at the problem and while reading i discovered hdd's got fuse , tvs diodes or zero ohm resistors as protection. I hope my problem is simple as removing this fuse so i need your help. I added several pictures of my pcb, to me it looks pretty clean; no apparent char etc. Please let me know if you see another problem on pcb cause i'm just guessing the problem with my newly obtained info about hdd's.

I removed this drive from old western digital my book portable drive case. I don't know much about electronics but i couldn't locate any zero ohm resistors or tvs diodes near power connector. Only thing i see is resistor R63. Is it the fuse i'm looking for?
I will get my pcb to local electronics shop (cause i'm not sure if i can find experinced pc hdd shop in my town) and get the fuse tested if i can locate it with your help. If I'm right, i should get that fuse removed and get wire etc. between two nodes of fuse right? I know doing this removes protection from secondary failure but I'll immediately transfer files and i'm pretty sure my mobo and pc is safe right now.

Thanks in advance.

Attachments

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hdd model

[pepe]

Please read this topic thoroughly:

https://forum.hddguru.com/viewtopic.php?f=1&t=39155

without checking preamp you can easily cause severe corruption (destruction) of data on the drive.

pepe

[fzabkar]

Did the drive fail when it was installed inside the My Book?

Do you have a multimeter?

[Prelektro]

pepe, thanks for the heads up. In one of your posts you mentioned that if cpu and rams are damaged, its likely 5V line . In my case, cpu, rams and gpus survived. Maybe my preamp is safe?

fzabkar, no i removed it from the case. Back then, i was gpu mining and used that drive for my mining pc. Maybe adding details of failure may help; i had 4 gpus running smoothly, than wanted to add 5. gpu with newly bought riser cable. After power up, one big white flash and pc dead. Mobo, hdd and psu died; gpus, ram and cpu survived. Actually, i was stupid enough to try adding 5. gpu two times , resulting 2 dead mobo and 1 dead hdd (the one i posted here) and 1 dead ssd. Psu survived first failure and died at secondary failure. I suspect that newly bought riser cable was faulty, because it was different than others or 5 gpus were too much for 1200 watt psu(it was zalman platinum) but if i remember correctly, i measured and 1200 watts were enough i don't know.

Unfortunately, i don't have multimeter i was hoping to get some info and get my pcb tested at some electronics shop but i may get one cause i want to educate myself more about electronics.

[pepe]

Guessing preamp status by other components survival state is quite risky, so i recommend testing the preamp itself.

pepe

[fzabkar]

The fact that the SSD died would point to an overvoltage on the +5V supply, in which case there is a high probability of preamp damage.

It appears that you may have done this:

Warning: do not interchange modular PSU cables:
http://www.hddoracle.com/viewtopic.php?f=56&t=2545

A cheap digital multimeter (US$5) is all you need for preamp testing.

I believe these are your test points:

Please confirm the Gnd test point by checking for continuity with a screw hole.

[Prelektro]

I believe these are your test points:

HDA_conns.jpg

Please confirm the Gnd test point by checking for continuity with a screw hole.

Thanks a lot for showing test points. I bought decent multimeter today and checked points you asked. GND test point checks for continuity. (Top row, third and fifth pins (from left) also check for continuity, dunno if it means anything just telling)

I measured directly on HDA pins, my readings :
-5V -- GND : 17.7 kOhm
+5V -- GND : 16.76 kOhm

well i checked other topics pepe suggested ( https://forum.hddguru.com/viewtopic.php ... 84#p276884 ) ,here; the readings are in M Ohm scale for good hdd. so my preamp is toast ? i don't have any other wd hdd to compare these readings

[fzabkar]

Not all preamps are the same. I would bet that your preamp is OK.

With your PCB off the drive, and powered up, can you measure the voltages at V1, V2, 3.3V and 5V ?

Also measure the +5V and -5V pads at the HDA connector.

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V1.jpg (128.47 KiB) Viewed 10545 times

3V3.jpg (65.49 KiB) Viewed 10545 times

[Prelektro]

Okay i had to google to learn how to measure things you asked but i think i figured ? please clarify for me

For V1 and V2, i put my black probe to one end of resistor and red probe to other end of resistor right ?

If that's correct :
V1: 5.32 V
V2: 5.32 V

Than for Smd transistor , I did like in my attached photo (black probe on bottom right leg of transistor (i guess its GND?), and red probe on legs you showed on your markings):

For +5V : 4.28 V
+3.3V : 0.007 V ?

Checked pads also (i did it like HDA pins (black probe on gnd pad - red on +5V and -5V) also pcb was powered )

+5V : 5.32 V
- 5V : 0.5 V

Attachments

haha.png (194.52 KiB) Viewed 10536 times

[fzabkar]

The black probe goes to ground, eg a screw hole.

[Prelektro]

Okay did it like that, most of the readings stayed same :

V1 : 5.32 V
V2: 0.000 V ( I get 5.32V if i measure other side of the resistor but no readings from where u marked)
5V: 5.32V
3.3V: 0.456 V

Pads :
+5V : 5.32 V
-5V : 0.510 V

[fzabkar]

The motor controller chip is dead.

[Prelektro]

Damn, i had some hope when u said my preamp would be okay . What are my options here than? I guess pcb swap and mcu transfer would fix it right, if i can get the same pcb ? (like this one :https://www.donordrives.com/wd-1tb-wd10eacs-00zjb0-2061-701474-600-01p-sata-3-5-pcb.html)

Smooth chip is the motor controller right? Any chance to replace it? but i guess it's far from DIY procedure. looks like i'll be asking for professional help at the end, how much it would cost me approximately?

[Prelektro]

By the way, which reading shows that problem is motor controller? (i'm just curious, trying to understand the problem even though i'm just newbie to electronics) thanks a lot for taking your time to help me.

[fzabkar]

The motor controller (SMOOTH) also controls the power supplies. All three power supplies are bad, so the SMOOTH IC is the common factor.

Unfortunately there is no chip at location U12 (the "ROM"), so a firmware transfer is not possible for your PCB. Instead you would need to regenerate the ROM from the System Area (SA) on the platters. That requires specialist tools, eg WDMarvel, but it is not a straightforward DIY procedure.

[pepe]

I measured directly on HDA pins, my readings :
-5V -- GND : 17.7 kOhm
+5V -- GND : 16.76 kOhm

check them with continuity/diode checking mode, not with resistance mode.
GND(black) to +5V(red) should be higher than 1000,
GND(black) to -5V(red) should be around 200,
GND(red) to -5V(black) should be more than 1000

if any of them has low value your preamp is toast.

pepe

[Prelektro]

GND - +5V : 0. 542 V
GND - -5V : 0.769 V
GND(red) - 5V(black) : 0.772 V

Well, rip my preamp too i guess?