Hello, I have a weird problem with my Optiplex 7010 SFF, I bought it used a few months ago, and it was working quite alright, all of the sudden in the past month I started experiencing this blinking orange power button the power comes on for a second then it switches itself off, I searched for answers all over the internet, the conclusion is "possible Motherboard Failure" however sometimes the computer actually turn on, which is the weird part, I tried a different PSU, same result, re-seated the cpu, ram, battery, updated BIOS and even unplugged everything but the 24-pin and 4-pin, same result, any idea what might cause this ? there is no burnt anything on the motherboard, and it does actually run from time to time, but not consistent.

Here is a video of the problem

https://youtu.be/a6mDp6dnyu0