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 Post subject: Modular PSUs are dangerous
PostPosted: June 12th, 2021, 19:22 
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Joined: June 12th, 2021, 19:12
Posts: 1
Location: United Kingdom
So, I have just had a bit of a re-jig of my PC (Mainly acting as a NAS with a couple of 14Tb HDDs).

After about 3 hours of trying to figure out why my HDDs won't power up I think I've worked out why. It isn't helped by the fact these drives are shucked from external WD Elements devices, and you need to run them from a molex to Sata to overcome the 3.3v power line issue they have.

At first I forgot this entirely and plugged them into a shiny new Sata cable from the modular PSU. Then I remembered and plugged them into the molex, but still no power. After lots of head scratching, I dug out the original enclosure a tried with the original power/usb board. Still no luck.

What I think has happened, is the modular cable I grabbed is from another PSU brand. If I'm reading the pinouts correctly, it looks like it may have delivered 12v to the 5v pin. There is absolutely no way to tell these cables apart except for looking at the pinouts - they all fit the same 6pin sockets.

Anyway I now have 2 very expensive paperweights. Fortunately I have the most important stuff backed up but it would be real good to recover them. I see no physical evidence of an issue. I see some posts about TVS chips being removable to recover them, but I have no idea how to identify.

If someone could help, it'd be great!

Thanks!


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 Post subject: Re: Modular PSUs are dangerous
PostPosted: June 13th, 2021, 7:22 
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Joined: November 7th, 2020, 5:31
Posts: 1084
Location: The_UK
Quote:
Modular PSUs are dangerous
Yes they are.
You'll be lucky if it's just the TVS - we can but hope. Assuming your pcb looks like the one I found online, take the pcb off and check the bottom left hand corner.

Diodes are the diodey looking things D3 D4 and check the resistors R64 & R67.

Attachment:
wde-14tb.PNG
wde-14tb.PNG [ 1.71 MiB | Viewed 9073 times ]

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 Post subject: Re: Modular PSUs are dangerous
PostPosted: June 13th, 2021, 14:51 
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Joined: September 8th, 2009, 18:21
Posts: 15463
Location: Australia
These newer [HGST?] drives are properly protected in most, if not all, cases. One would be very unlucky if they were not salvageable by removing the shorted TVS diode and replacing/bridging the fuse.

Edit:

[url]https://www.truenas.com/community/threads/wd-14tb-elements-for-£189-99-at-amazon-uk.89635/[/url]

The drive appears to be a HGST helium model -- WD140EDFZ-11A0VA0


Is this your PCB?

https://i.imgur.com/DmbozQR.jpeg
https://imgur.com/a/UxKwqS7

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 Post subject: Re: Modular PSUs are dangerous
PostPosted: June 13th, 2021, 15:01 
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Joined: November 7th, 2020, 5:31
Posts: 1084
Location: The_UK
This more appropriate ?
Attachment:
wde-14tb_2.PNG
wde-14tb_2.PNG [ 1.02 MiB | Viewed 9016 times ]

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