U5 and U6 output shorting to ground

[Tiki]

Hi,

So, this all started with me accidentally using a 12V power supply and basically instantly breaking my pre-made OSSC. I replaced F1 and D5 after finding that they were both broken, but my unit still didn’t show any signs of life, so I also replaced U5 and U6. Still nothing, but now I’ve realized the output pins of U5 and U6 are shorting to ground. I checked all of the voltage regulators for shorts to ground, and here is what I found:

U5 – Output shorts to ground
U6 – Output shorts to ground
U7 – Input and EN short to ground
U9 – Input and EN short to ground
U12 – Input, EN, and Output short to ground
U13 – Input and EN short to ground
U14 – Input and EN short to ground
U15 – Input, EN, and Output short to ground
U16 – Input and EN short to ground

I’m good with soldering, but have a limited understanding of circuitry in general – what are my options here? Do I have a shot if I just replace all the voltage regulators, or does this mean something is wrong with the FPGA or something else?

[Deleted User]

Chances are you fried quite a bit there.

Just replacing parts is probably going to take the longest time…

I can have a look at the schematics.

Basically, your plan of attack would be to identify the damaged parts by removing pieces and checking if the short persists down or upwards of the rail.

First, I’d have a good look at all parts. Visual inspection is important!

You can remove the regulators and then check for shorts again.

[Tiki]

Thanks! I think I’ll start the process of removing parts to identify what’s fried near the end of this week. Upon visual inspection under a 10x magnifying glass, nothing immediately jumps out as alarming…

[Author]

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