PC posting behaviour is very inconsistent.

[Achanar]

Specs:

Motherboard: Gigabyte H97 D3H

CPU: Intel i5 4570

RAM: Patriot Signature 8gb (2x4gb) DDR3-1600

GPU: Sapphire R9 290 Tri-X OC

PSU: EVGA 750G2

Storage: Samsung 850 evo 120gb, Seagate Barracuda 1tb

OS: Windows 10 64-bit.

I built this PC in July, though the GPU, RAM, CPU, and HDD have been used for almost two years.

A few days ago I turned on my PC only for it to fail to post and instead powder itself on and off. Occasionally Gigabytes dual BIOS would kick in with a single beep from the mobo speaker however it would power off just the same.

First I tried testing the RAM. Interestingly every time I reseated them in different slots I would be able to boot at least an couple of times into either the BIOS (if I had tried resetting CMOS prior, which never helped) and/or into Windows. However after a few reboots it would go back to looping OR would enter a different state where it wouldn't poost but it wouldn't power off either, the motherboard speaker would also tick every few seconds with a steady rhythm.

Most recently I yet again moved the RAM and actually got to reboot right into Windows a dozen times before it broke again.

After this I found that turning off the PSU and letting it drain could cause it to change from looping off and on to staying on with the ticking, and visa versa, though only rarely. Previously it had the same behaviour until I moved the RAM again.

In addition the CPU fan would stop spinning immediately after power on unless a BIOS kicked throughout troubleshooting.

I have also tried to see if anything is loose or if there is anything that could be causing a short but have found nothing out of place.

Whenever I did get into Windows everything was normal. I could browse, play games, browse files and run scans without issue. Everything would be normal until I shut it down and it stopped working again.

Notably immediately prior to the start of this issue I had a severe software issue from an update to Kaspersky 2016 that prevented Windows from even booting into safe-mode. I had to reset Windows 10 in order to fix it and reinstall drivers, including motherboard drivers.

[Nite-Ninja]

Something isn't right with the power delivery somewhere. Might be symptoms that your power supply might be kicking the bucket. If you have a little extra coin, get yourself a power supply tester (or find a spare PSU in the closet with the following connectors) and ensure that the 24 pin rail to the motherboard is good, as well as the 8 pin to the CPU, both will cause the system to behave as such. If the tester after several tests shows that the PSU is good, might be the motherboard going on you.

[Achanar]

Something isn't right with the power delivery somewhere. Might be symptoms that your power supply might be kicking the bucket. If you have a little extra coin, get yourself a power supply tester (or find a spare PSU in the closet with the following connectors) and ensure that the 24 pin rail to the motherboard is good, as well as the 8 pin to the CPU, both will cause the system to behave as such. If the tester after several tests shows that the PSU is good, might be the motherboard going on you.

maybe I'll have a chat with EVGA if possible about the possibility of it being a PSU issue. I've heard that EVGA are great when it comes to support.