The computer struggles to start up but functions properly once it does.
The computer struggles to start up but functions properly once it does.
I've owned my computer for several years now, and lately it's been acting up. The startup has become unpredictable. When I press the power switch, it attempts to activate, the fans kick in, and then it shuts down. It loops repeatedly, sometimes restarting, other times stopping entirely. At times it halts completely, while at others it seems capable of continuing if left on. I've attached a video for reference. The second attempt in the clip was independent. It usually tries longer, and occasionally it persists until I manually power it down. Occasionally it functions, and I've managed to spot a pattern, though a fix remains elusive.
Initially, I connected my CPU cooler to the CPU fan connector at the top of the motherboard. It would spin up reliably during successful starts. I was concerned at first, suspecting a faulty header, but later tried other connectors. One worked consistently (the one in the video). Since the system still wouldn't boot, I suspect the issue isn't with the fans. Perhaps switching the power supply off, waiting briefly, and restarting helps.
Occasionally, connecting case fans to non-working headers only functions after a proper start, not during failed attempts. Sometimes simply turning off the PSU and waiting a moment before trying again resolves the problem. The most curious aspect was that it sometimes worked when the side panel was off—probably just a coincidence.
I tested the power supply using its self-test feature; it passed, so that's unlikely. Another unusual fix involved resetting the RTC RAM with a jumper on the motherboard. I found this mentioned in the manual and it quickly resolved most issues. It only took a few tries to get it working again today.
Lastly, relocating the CPU cooler to another fan connector revealed a subtle clue: before a successful boot, the GPU lights up white, but once the system starts, it changes to purple—a custom color I use. Research suggested this might relate to the CMOS battery or a short in the PSU. I cleared the RTC RAM with a jumper and saw results quickly.
I'm still unsure, but given my age, any component failure seems plausible. The PSU passed its self-test, ruling that out. The CPU cooler issue appeared only after I powered it down. Other forum users reported similar patterns—boot loops without a full shutdown. My specs are: Asus Sabertooth X99 board, i7 5820K CPU (base voltage), GTX 1080 BeQuiet Dark Rock Pro 4 cooler, Corsair AX860i PSU, and a Cooler Master Mastercase Pro 5 case.
I'm seeking a second opinion before making any changes.