PC Boots but wont display to monitor or power peripherals + Red CPU LED

omegatre

Reputable
Dec 30, 2014
5
0
4,510
Hello, I am in need of assistance.

My computer worked fine earlier today.

Summary:
1. I changed out my CPU air cooler for a liquid cooler today.
2. Computer boots and all is well.
3. CPU temps are a litte high, jumps from 35-53 C with only HWmonitor running.
4. Decide to replace thermal paste.
5. Now the PC boots, but I get a RED CPU LIGHT and no power to peripherals or monitor.
6. I shut down and dismount the CPU cooler and almost everything else and then reassemble.
7. Now the PC boots fine.
7.1 I Run Prime95 to check temps
7.2 I find the temps not to my satisfaction 70+ C (I expected better from a CM Nepton 240M), so i try tightening the CPU Cooler while PC is on. I Tighten 1 screw OK, try one more and the PC shuts off. (Not sure if random or if the screwdriver killed it)
8. Now I am back to "step" 5 with no solution

I have tried unplugging everything, switching PSU etc.

My next step would be to replace the CMOS battery, but from what I've read that's only relevant when the PC wont boot.

PC specs:
- i5 3570K @ 4,5 GHz
- GTX 770
- ASUS Sabertooth z77
- Corsair TX 750w
- 2x8 GB HyperX DDR3 RAM
- Cooler: CM Nepton 240m (previous cooler: Noctua Air-Cooler)