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Old 04-03-2018, 07:57 PM   #1
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Join Date: Apr 2018
City & State: Ft. Lauderdale, FL
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Posts: 14
Default Shuttle SD36G5M - Mobo died, recapped, still issues

Hi everyone,

New to the forum. Great wealth of knowledge on here, wow! I'm hoping some of you can help me out. This is gonna be long as I throw out my back story here.

I have an older Shuttle XPC SD36G5M that I bought off ebay for cheap a couple years ago. I use it as a home theater computer and has been running fine until 2 weeks ago. It went to sleep and never woke up again. Pushing the power button would get the fans to jerk and that was it.

I bought a new power supply figuring that was the problem, but had the same results. That's when my internet searching brought me to this website. There was one OTC cap that was visibly bulged on top. So I decided to recap the whole board.

The first thing I did was replace the bulged cap and see if that would fix things. The fans spun for about 1 second this time before the board would turn off. Then I recapped everything else and sure enough it fired up and worked!

Then, again, the computer went to sleep after some online streaming, I woke it up and shut it down and it hung at shut down. Ever since, it has been freezing whenever doing something somewhat "intensive," such as opening Google Chrome, installing Windows, or running a memory test (freezes at 10% every time, no matter what stick or how many are installed). It would also hang at one point just copy pasting files. Something is unstable, maybe RAM? It will stay in the BIOS no problem. It also seemed to have no issue sitting on the Windows desktop without anything running.

What I did notice is that the whole side of the board where all the caps are and where the PSU plugs in gets very hot. Abnormally hot. So hot that all my new caps get very hot to the touch. Today, I turned the computer on from being off for a day and felt around. I found one SMD Mosfet(?) that was so scorching hot it burned my finger (right next to the first cap that was bulged and replaced). Not long after having the system up, all the adjacent caps got pretty hot. Heat radiated from there and seemed to slowly heat everything on that side up.

Now for all my questions...So from reading it's possible the mosfet is toast. Would that happen from the cap going bad? Is the hot mosfet the actual problem now or something else causing it to draw a ton of current? And if I replace it, what are the chances something else is damaged and the system will still be unstable?

Lastly, I replaced all caps with Nichicon. After reading some more, my concern is with the ESR. Most are HV, some are HM, and some are HE Nichicon caps. Are those acceptable or part of my problem?

Thanks so much for the help!

Last edited by racer2086; 04-03-2018 at 08:03 PM..
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