Device fails to start on power but works occasionally with BIOS access.
Device fails to start on power but works occasionally with BIOS access.
Hey, I assisted a friend in assembling a PC about a year back. Now he’s facing some electrical problems, and I’m running low on suggestions. A few months ago, the machine would fail to start after a couple of days. Pressing the power button yields nothing—no fans spinning, no Power LED flashing, even the diagnostic lights stay off. The RGB stays blazing, but the PC won’t turn on. It does receive power through the RGB, which is always active. After trying a stripped-down setup and switching power supplies, we still couldn’t get it to boot. Eventually, we went back to the motherboard and after a long wait, received a warranty replacement. We swapped in a new board and tried again, but the issue persisted. We also tested a RAM stick that resolved the constant RGB glow, so we suspected that one of those might be faulty. We found another RAM module that worked fine. After all this, we sent the CPU back for repair, obtained a warranty replacement, and purchased a different RAM kit. Now with the new board, CPU, and RAM, we attempted booting once more, but it still wouldn’t start. On the first attempt using BIOS FLBK, the RAM error light flashed. After several tries to fix BIOS issues via FLBK, the PC would suddenly power on. We entered BIOS, even reached Windows, and pressed Restart in Windows—it restarted properly. Then we shut it down. When we pressed the power button, nothing happened—no lights, no fans. Experimenting with BIOS FLBK again, the system would boot after a few presses. Eventually, a BIOS update helped, but nothing else worked. Disabling fast boot and turning off FTPM didn’t resolve it. Once we updated BIOS, it still wouldn’t start. After a 15-minute OCCT stress test on CPU, RAM, and GPU, everything functioned correctly. Now we’re at a loss. It’s confusing—why does the power button do nothing, yet sometimes the BIOS FLBK button gets the job done? Anyone have any insights?
Components: CPU – AMD Ryzen 7 9700X
Motherboard: Asus Strix x870-a gaming
RAM: Trident Z 5 Neo RGB, 2x16GB
GPU: PNY GeForce RTX 4080 Super XLR8 Verto Epic-X
CPU Cooler: Noctua NH-U12s
Case: LianLI O11 dynamic EVO
Power Supply: Seasonic Prime TX-1000
SSD: Samsung 990 Pro
Summary: The power button remains unresponsive, but BIOS FLBK occasionally initiates startup. Once the PC boots, it operates normally in Windows, though a forced restart is required. No lights or fans respond.
That happened really quickly! I didn't realize it was that simple. It's definitely not the power switch. The same thing happens with the startup button on the motherboard. Also, there were times when the PC would boot up and then fall asleep after a while. When we came back, it would wake up properly. We could turn it back on using the power button. No problems with the button itself, but it's not ideal.
Make sure to test his advice further. Unplug the power switch from the MB and use a screwdriver to connect the two pins, then check if the device powers up.
We also attempted that. It happened more by chance since we both overlooked the Start button on the motherboard. The initial board lacked this feature, so we had to use an alternative method with the previous one. The replacement board features the x870 chipset, whereas the first model had the older x670 (Asus Strix x670E-A gaming wifi). The older version is no longer available, so we chose the newer one for learning purposes. To understand the difference between shorting the pins and using the Start button on a board.