The computer fails to power on because the 8-pin connector isn't connected to the motherboard.
The computer fails to power on because the 8-pin connector isn't connected to the motherboard.
You're using the proper cable. By Saturday your computer functioned well until it ceased when attempting to remove dust from your AIO filter.
Search for damaged parts on the motherboard, inspect RAM/PCI-e connectors for dirt or dust, examine CPU pins, and so on.