I'm posting this message because I've had an intermittent problem with my computer for over a year now and have never been able to find out what the issue is despite extensive troubleshooting and discussions with ASUS support.
Turning the computer on is like a lottery, sometimes it will boot up straight away with no issues, sometimes it will not POST. When it fails to boot, I get a "no signal" message on the monitor and no power to any of the peripherals. The QLED display on the motherboard shows "C6" and there is an orange DRAM light.
If I repeatedly hit the reset button on the case, eventually it will boot but this could take 1 try or 20.
Troubleshooting steps taken:
Reset BIOS settings to default
All RAM sockets tested and in various different combinations (1 stick, 2 sticks etc)
RAM with default timing
RAM with DOCP settings applied
Tested RAM using the windows tools (all sticks reported OK)
Operating system reinstalled
Full system rebuild (more than once!)
Tested different combinations of peripherals and booting only with the essentials attached.