PC "no signal" upon booting?

[woodson]

Have an issue where a PC is powered on, but no signal to the monitor. Problem is not consistent though – after unplugging the power cord for a while, sometimes it works.

 

Specs. are a 2014/15 Pentium G, 4GB DDR 3, Asus H81M+  mobo, Corsair 430 watt PSU.

 

Troubleshooting so far: 

 

- Checked seating of all cables and RAM.

- Tried swapping RAM to different slot

- Power cycled

- Tried brand new PSU

- Tested RAM with MemTest86

- Reset CMOS by removing battery.

- Tried different monitor cables (DVI and VGA - have not yet tested with an HDMI connection)

- Ran Crystal Disk on the HDD - no problems 

 

Funny thing is, it's fine when just restarting (as opposed to powering down completely and starting up again). But if I try to boot from scratch twice in a row, I get 'no signal'the second time. Only way to get it working again is to power down and unplug for a few minutes.

 

Any advice is gratefully received at this point. Pulling my hair out!