Troubleshooting a Peculiar Computer Issue: Seeking Guidance

Lately, I’ve encountered some rather unusual behavior from my computer, and it’s reached a point where I can no longer ignore it. Allow me to provide a bit of background. About three years ago, I had my computer repaired after receiving a subpar replacement part from an unidentified vendor. Since then, it has exhibited several oddities, starting with a persistent CPU fan error message, despite functioning fan and normal CPU temperatures. Rather than seeking assistance from the technicians, I attempted to troubleshoot it myself.

My next challenge came when Windows began demonstrating signs of failure. After some investigation, I concluded that a faulty SSD was to blame, which I eventually replaced. This resolved the issue temporarily, but more problems soon followed.

Currently, when I attempt to power on my computer, it behaves inconsistently. At times it turns on without a hitch, while other times, it simply doesn’t. When it fails to start, the power button illuminates, the power supply appears operational, and all components seem to be in order. However, I notice that the keyboard, mouse, and monitor remain unresponsive.

The situation often demands a series of attempts: I frequently have to turn the system off and back on repeatedly, switch the power supply on and off, or even disconnect and reconnect everything inside the case. Strangely enough, everything appears to be connected properly each time I check.

Despite these startup quirks, once the computer does boot up, it functions smoothly—most of the time. However, there are instances when switching the HDMI connection from my monitor to the TV results in an unexpected restart. Additionally, the system can shut down if it’s nudged, even slightly, and random shutdowns occur on occasion.

I am reaching out to this community for help. If anyone has experienced similar issues or possesses any insights on diagnosing or resolving such peculiar behavior, your advice would be greatly appreciated.

For context, I have shared images and videos of my setup, which you can view here.

Thank you in advance for your assistance!