Not sure if I blew a 5v tvs diode or not

SO, I somehow wedged a drive fan power adapter in the end of my drive upside-down. Even though it is keyed specifically to prevent that. I know, I know. it is a horrible thing. So I basically had 12v on the 5v rail and 5v on the 12v rail. And now the drive will not spin up when powered normally.  I’ve pulled off the logic board and there is no sign of charring or burning near the two diodes next to the voice coil contacts. I tried to test them at 200ohm on the volt meter but im just getting a 1 when testing both directions, on both diodes. So i can’t really tell if these were blown or not. I have a spare drive that I can swap parts from if needed, but now im not sure if the over voltage did something worse then just blew out the TVS. 

Any thoughts?

Also here are the specs for the drive

MDL:  WD1200JB-00FUA0

Date: 06-September-2006


SN: [Deleted]

Size: 120GB

Here is a pic of the board.

The plastic on the MCU is from the shield between the board and the case. I’m starting to suspect the worst.

Check the posts by fzabkar he has helped people with board problems like that. Sometimes you can bypass the bad diode. Or you can try sending him a PM.


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Thanks for your response Joe.

I guess the thing im worried about now is if that little bit of plastic and the tiny hole in the shield are enough of an indication that i’ve blown out the MCU. I’m also wondering which one is the 12v and which one is the 5v. I’m a little paranoid about messing it up further. From what I can tell, C59 is the 5v and C62 is the 12. Just wanna make sure before i go snipping these things off and testing again.

Fzabkar looks like he is pretty regular around here so for now im going to sit on my hands. Working tech desks has made me loath actively bothering other people with issues that they might find easy. It’s much nicer to just stumble across a problem and then share needed info.

Thanks again for your response.