Pc will work for short periods of time

[lewis.vaughn1995]

My PC is a home built using these parts (https://pcpartpicker.com/list/sn8yZR
CUK Mantis Full ATX Tower Gaming... https://www.amazon.com/dp/B07GQ4YJB6?ref=ppx_pop_mob_ap_share ) and had been working since July 2018 until sometime mid Nov. 2018 with no issues. Then suddenly the screen flickers and no signal is being sent to my dual monitors. The fans still run and the motherboard and graphics card still light up. After reseating gpu and ram sticks and also testing the pc without one part or another it wouldn't send signal but sometimes for seemingly no reason it would work anyway (after putting everything back in). I took it to Best Buy' s Geek Squad and was told it may be because the motherboard is fried due to one of the screws holding it down not being tight enough. I was going to send the motherboard back to ASUS as recommend but some of the screws pop back into place when I tried unscrewing it even when I tried living the motherboard slightly with screw to get it out. Frustrated I put everything back and gave it one last try. Amazingly enough the pc worked again for about 30minutes before returningto it's no signal state. That latest test was yesterday. So my question being is this still the fault of a bad motherboard and if so, how to remove the screws that pop back in?

 

[Ralston18]

The good news is that if the motherboard does work, even if intermittently, then it likely not to be "fried".

I am wondering if you overtightened the screws and perhaps caused some minor crack or interim electrical short?

May be okay at first but then as things heat up some expansion occurs and then shorts out.

Are you able to take a couple of photographs to show the screws and locations?

http://www.tomshardware.com/faq/id-2373240/upload-image-imgur.html

 

[lewis.vaughn1995]

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The good news is that if the motherboard does work, even if intermittently, then it likely not to be "fried".

I am wondering if you overtightened the screws and perhaps caused some minor crack or interim electrical short?

May be okay at first but then as things heat up some expansion occurs and then shorts out.

Are you able to take a couple of photographs to show the screws and locations?

http://www.tomshardware.com/faq/id-2373240/upload-image-imgur.html

 

[Ralston18]

Those screws do not look right....

Did they come with the motherboard along with some stand-offs and non-conducting washers?

Compare the screws you are using/used to the photos in the following link:

https://www.ebay.com/b/Motherboard-Screws/51064/bn_7023225131

Take another look at the motherboard installation/mounting instructions.

If my assessment is correct, you may need a "do-over" on the motherboard install.

Hopefully someone else will view the photos and provide additional comment; second opinions recommended.