Question Solid red LED on CPU during POST

[CosmicBourbon]

So I've recently built a PC and despite having a few issues previously with the red LED's staying on, I managed to figure out the issue and everything was fine. A month later, I moved the case, took the side panels off with the intention of doing some cable management, finished the management and turned on the PC. Then during POST I had issues with the red LED staying on for the GPU, which I thought was a mounting issue as it had been previously. It got to the 'American Megatrends' screen and wouldn't respond to me pressing F1. So I unsecured the MOBO and plugged in the GPU again so it was definitely seating properly. I rebooted and the solid red LED had disappeared for the GPU but appeared for the CPU.

I've ensured multiple times that every connector is in properly as obviously something hadn't been fixed as it should've, which is presumably why I started getting issues just after moving the computer. The mounting bracket is secured to the MOBO and the the cooler is fixed properly to the bracket, although there is a very slight gap where the clips don't fit 100% onto the bracket clips so there's a small amount of movement. Could this be the cause? Any help would be appreciated.

I've attached a few pictures of pre-startup then after turning it on, and another of the bracket, excuse the non-existent cable management .

https://postimg.cc/r0KwRQKX

attach2 — Postimages

postimg.cc

https://postimg.cc/HcQPzCJQ

Specs:
M5A99X Evo
GTX 760 2GB
FX 6300 6 Core 3.8Ghz
12gb DDR3

 

[gingerrankin]

The thermal paste between the cooler and the cpu solidifies with time. If the cooler does not move at all, this has little relevance, but if the cooler moves much of the cooling power is lost.

Although it is strange that this, by itself, causes the red light of cpu, to discard topics I would tell you to verify why the cooler moves and replace the thermal paste.