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Data recovery and disk repair questions and discussions related to old-fashioned SATA, SAS, SCSI, IDE, MFM hard drives - any type of storage device that has moving parts
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Help identifying diode to remove on shorted Hard drives

June 28th, 2020, 18:01

Hi all,

I was replacing my power supply (EVGA modular) with a Seasonic (modular) and the existing EVGA modular sata plugs seemed to fit perfectly into the seasonic so i tried to be lazy and use them instead of using the actual seasonic cables. Computer wouldn't power one, so used the correct cables and it came on, but all 3 of my spinning hard drives no longer spin up. I read you can remove a diode that's used like a fuse to bring it back to life. I just need help identifying the fuse.

I'm going to try it on my old hitachi 2TB first, attached is a picture.

Any help identifying it would be greatly appreciated. I think it may be the tiny green vertical fuse in the top left of the picture when the sata port is facing left (Picture is rotated in thumbnail), as it appears to be shorted on my voltage meter.

Thanks.
Attachments
20200628_174802.jpg

Re: Help identifying diode to remove on shorted Hard drives

June 28th, 2020, 18:20

TVS Diode FAQ:
http://www.hddoracle.com/viewtopic.php?f=100&t=86
Attachments
TVS_fuse.jpg
TVS_fuse.jpg (189.67 KiB) Viewed 12840 times

Re: Help identifying diode to remove on shorted Hard drives

June 28th, 2020, 21:30

Thanks for the reply. The fuse that goes into the 5V TVS was definitely blown. I shorted the fuse with a small wire, but the drive still won't spin up. Do you think i should try removing the 5V TVS.
I do get resistence across the 5V TVS, but it's half the resistence of an identical working drive i'm comparing it with (same model).

Re: Help identifying diode to remove on shorted Hard drives

June 28th, 2020, 23:41

It appears that there is damage elsewhere on the PCB, and possibly a damaged preamp as well. I would transfer the 8-pin 25FS406 IC to a replacement PCB. Suppliers such as hdd-parts.com include a free firmware transfer in the price.

What are the model numbers of the other HDDs? Seagate HDDs tend to survive such overvoltages, but WD's often do not.

Re: Help identifying diode to remove on shorted Hard drives

June 29th, 2020, 8:10

Here are the model numbers:

Hitachi 2TB: 0F12117 (HDS5C3020ALA632)- Shorting fuse and removing 5V TVS did not work
WD 8TB: WD80EFAX-68LHPN0 - Shorting blown fuse did not work
Seagate 8TB: ST8000DM004 - Have not removed control board yet.

Is it possible to read/flash the bios on donor board with one of these?

https://www.amazon.com/KeeYees-SOIC8-EE ... 626&sr=8-2

Any suggestions?

Re: Help identifying diode to remove on shorted Hard drives

June 29th, 2020, 19:07

Here are the drives. I tried to post earlier today, but it never went through:

WD80EFAX-68LHPN0 - 0J45413 BA6159A - Tried to short the blown fuse - Not successful
HDS5C3030ALA632 - 0J11430 BA3895A 2TB - Tried to short the blown fuse did not work so I removed 5V TVS, Stil does not spin up.
ST8000DM004 - 100802503 REV A - STICKER 2504 G - Have not removed PCB yet.

Re: Help identifying diode to remove on shorted Hard drives

June 29th, 2020, 20:02

You shouldn't be shorting fuses without confirming that there is no other damage. My FAQ specifically warns against this.

Did you measure the TVS diodes in the WD80EFAX?

Re: Help identifying diode to remove on shorted Hard drives

June 29th, 2020, 23:56

Both are measuring around 123 ohms on the WD.

Re: Help identifying diode to remove on shorted Hard drives

June 30th, 2020, 7:15

I found the pinouts for the evga cable and the seasonic cable. Looks like when i plugged the evga cable into the seasonic power supply, it sent 12v on the 3.3v rail, and sent 3.3v and 5v on the ground rails... This probably doesn't help to troubleshoot it, but i can definitely see why it died now.
Attachments
Seasonic-Type-1-Cable-Pinout-SoloSleeving.jpg
seasonic
EVGA-G1-G2-G3-G5-GM-B3-P2-T2-Cable-Pinout-1.jpg
evga

Re: Help identifying diode to remove on shorted Hard drives

June 30th, 2020, 17:12

jmandawg wrote:Is it possible to read/flash the bios on donor board with one of these?

https://www.amazon.com/KeeYees-SOIC8-EE ... 626&sr=8-2

The LE25FS406 is a 1.8V part:

https://www.reveltronics.com/downloads/datasheet/le25fs406.pdf

That CH341 programmer is only suitable for 3.3V parts.
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