Zend certified PHP/Magento developer

VGA debug light on

I am building a computer, here is the component list :
https://fr.pcpartpicker.com/list/Ch8dwg
The problem is, the computer turns on but there is no display. And the VGA EZ debug led is red on the motherboard. The GPU, RAM sticks are lit with their RBG lights so I’m assuming they are functionning properly.
I have tried many things:

  1. Unplugging, repluggin the GPU
  2. Removed a RAM stick to leave only one
  3. Cleared the CMOS by removing the battery, waiting 15 minutes and putting back in.
  4. Cleared the CMOS using the jumper.
  5. Tried plugging a 1050Ti that doesn’t require any power supply, this GPU worked perfectly well on my previous setup.

I’m at loss at where the problem might lie. I suspect it is not the GPU’s fault, as I have tried plugging it on and off several times, and the RBG light is on. I could be using the wrong PSIe cables tho (Thing is, it still doesn’t work with the 1050Ti so I suspect it is not the problem).
I do not think it is the RAM’s or CPU’s fault either as their debug lights are not lit.

How to solve the issue?