PC doesn't boot, sometimes boot loops, works fine when it does boot into windows

ice2kewl

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Mar 7, 2008
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Hi guys,

I recently upgraded and clean installed Windows 10. I also performed a clean up of the system hardware (cleaned out accumulated dust, vacuumed some hard surfaces and fans, was somewhat careful not to get the vacuum close to components).

Since doing this, my pc started having boot up problems. I would turn the pc on and there would be no video output and my fans wouldn't slow down (normalise). I would turn off, boot again and the pc would boot with a message of boot failure and would give me options to boot with default bios settings. Once in Windows, the pc would function perfectly fine. Rebooting would cause the issue again. This continued for a few days and then got worse; It wouldn't boot successfully at all nor would prompt the boot failure option. I'd disconnect and reconnect some components (ram, gpu, hdd) and it would work again. Rebooting would cause the boot issue again. It got even worse, the pc would go into a boot loop (tries to boot, turns off, then turns on by itself, repeating this process). Again, I'd disconnect and reconnect components and the pc would work again.

Specs:
- Gigabyte z87 d3hp motherboard
- i5 4670k cpu
- dual 1600 MHz corsair vengeance ram
- nvidia 970 gtx
- xfx 650 watt psu
- (I don't have a motherboard speaker, I should get one)

I'm completely stumped as to what the issue could be. It doesn't make sense that the pc works perfectly fine once it does boot into windows. When I did have the pc boot loop issue, I tried with ram sticks out and with single ram sticks; The boot looping continued. So that ruled out ram issue.
I tried with gpu out; The boot looping continued. Tried with hdd out; Boot looping continued. Then put it all back together and it worked. WTH??

Today i checked the cooler fans and the roof fans connections. (This required me to remove and refit the ram). Didn't help. I put the hdd drive in sata 1 (instead of sata 0) and the pc prompted a no boot device error rather than failing to boot. Put back in sata 0 and bang, the pc booted. Used for couple of hours no problem. Tried to reboot and again the same issue of reboot loop.

I had a similar issue with another pc which would random boot (from initially being turned on to even rebooting when windows had loaded). This turned out to be a PSU issue.

Please help.

Thanks