I built this PC a little over a year ago, and it's been fine. I don't use it much, mostly stick to my laptop. But a couple weeks back, it wouldn't POST. After messing around with it – unplugging stuff, holding the power button – I found that if I hold the power button and flip the power supply switch on and off, it boots up. Then it runs fine for hours. anyhow I made it work by holding down the power button and flip the power supply switch on and off until now. I even left computer unplugging it from the wall and leaving it disconnected overnight, but this did not resolve the issue. The computer now only POSTs after either holding the power button while toggling the power supply switch.
So, it’s not the power supply. I found my old build and swapped in the power supply for testing. with that power supply it does same.
After messing around in the BIOS today, I downgraded to version 3072, which is the version that previously allowed me to get it to post/boot using my method (pressing the power button while toggling the power supply switch). But now, that method doesn’t work anymore, and I’m stuck on the yellow light.
pressing the power button does nothing—no fans, no QLED check light on the motherboard, nothing. The only light I see is a blinking green light near the BIOS flash. when I use the method (pressing the power button while toggling the power supply switch), the machine does post, the fans spin, and the motherboard light turns yellow. Another thing, as soon as I plug my PC to wall no nothing and wait about 4-5 secs I see BIOS FLBK green blinking on back I/O.
Also, none of the drives are plugged in—only the DP cable is connected. (no usbs, no keyboard, no mouse nothing)
Flashed BIOS versions 3057, 3067, 3072, 3208, and 3222 (results were the same or worse).
Swapped in a power supply from an old build (no change).
Replaced the CMOS battery (2032), but still no luck.
