Question WD120EFBX WD RED Plus 12TB

Jan 11, 2025
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Hi all,

I'm having an issue with 3 12TB WD hard drives. There was an issue with my plex server not staying on and I was attempting to troubleshoot it. The PC was start POST and then immediately shut down. I have a separate PC that runs a home arcade I built a couple of years go. I figured the power supply may have gone bad and my Aracde rig uses the same PS. I made the connections using a temporary off/on switch and the unit powered up without issue. Unfortunately while doing this at some point I messed swapped the SATA power cables. It seems I did something similar as this poster: https://forums.tomshardware.com/threads/wd120efbx-wd-red-plus-12tb-no-longer-initialized.3792102/. Three of the drives are not powering on. I've been reading posts and found the following information:https://www.hddoracle.com/viewtopic.php?f=100&t=86. I'm doing my best to try and fix the issue but need some help. I pulled the board from one drive (see attached)
Board Pics. I don't see any obvious damage. In one of the images, I've circled and numbered the parts I believe I need to begin testing with my multimeter. Before I go any further I was hoping for some guidance I which ones I should start with and what numbers I should be looking for. I've tried to include as much information as possible. I appreciate any help.

Thanks!
 
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The "74" diodes would be OK (unless the supply voltage was reversed). The usual culprits are the 5V fuse and 5V TVS diode (SUA).
Thanks for replying. I appreciate it.

The supply voltage wasn't reversed (I don't think). Was able to get the PC to reboot and Windows started up. However, the 3 12TB drives weren't active. Another 4TB drive was fine and the SSD boot drive was working. When I noticed they weren't active I discovered I had swapped SATA power cables by accident. I fixed the issue with the SATA power cable but at that point, I think the damage was done. I pulled out the multimeter and this is the reading I'm getting from #3 and #6 in my previous marked-up image.