HP Pavilion Desktop (TP01-2234) does not power on

[Slasher-I7]

So roughly 14 to 16 hours ago, I had my PC shutdown like normal. Fast forward to this morning, the PC does not turn on whatsoever. I've opened it up to see what was wrong and there were no visible signs of anything. Just in case it was not clear, my PC model is a TP01-2234, the motherboard is HP8906/Erica6. After doing some light research and talking to AI, here's what I did so far to try and solve this issue.

1. Cleared CMOS.

2. Tried powering on PC without the button, but I dont think my motherboard (Erica6) has the pins for this jumpstart method.

3. I replaced the PSU months back, so to ensure it wasn't a PSU issue, I reinstalled the stock PSU that came with it. No luck.

4. I pressed the power button for some time, with the PC unplugged, for discharge. It still didn't turn on after plugging in the power cord.

After fiddling around with the PSU pin connectors, I noticed that after unplugging a 4-pin from the SYS_PWR header, the PSU runs. Plugging it back in turns the PSU off. AI told me it was related to how the motherboard communicates with the PSU, and suggested that the motherboard could be dead, hence why the PC doesn't power on.

Obviously AI is not perfect, so I just need some more opinions on this, if possible.

[Slasher-I7 · Accepted solution]

UPDATE: My PC is working fine again as far as I can tell. Im not sure what fixed it, but for those interested in exactly what happened: after taking a look in my case again, I took out a RAM stick, and then eventually both of them (i have 2 total). Not sure how but at some point I noticed the LED on. After taking out the two sticks and turning it on, it did the 3 beep thing, which I assume was due to the RAM slots being empty. After putting one back, I realized it could display again. It prompted a bit locker recovery key, and eventually it all went back to normal. Obviously I had it turned off several times in between taking out and placing the RAM sticks.

Im going to leave this unsolved for a few days or so, to give it time just in case it breaks again.