After opening PC and giving a clean it's not working (RAM)

The problem might be a combination of things. First, I'd use the latest non-(.CAP) BIOS specifically v1203 (.ROM) - http://www.asus.com/Motherboards/I [...] /#download and update either by ASUS EZ Flash 2 or USB BIOS Flashback - http://event.asus.com/2012/mb/USB_ [...] ack_GUIDE/

The 8GB/stick can be a PITA to keep stable in consumer RAM kits.

There's (3) three 4x8GB DDR3-1600 kits and here's my observations with the 8GB/stick density:
PV332G160C9QK 9-9-9-24 @ 1.50v ; harder to keep stable CAS 9 @ 1.50v
PGQ332G1600ELQK 9-9-9-24 @ 1.60v ; easier to keep stable CAS 9 @ 1.60v but it depends on the VCCSA
PV332G160C0QK 10-10-10-27 @ 1.50v ; probably the easiest to keep stable of the (3) listed

The above may help you. I found that Here

crazykilla said:

I've made no changes other thsn where the ram is.

You didn't take the CPU out and apply new thermal paste?

Guys i fixed it, the problem was 1 microscopic tiny peace of dust in between the processor and the pins on the mb,
Oh and since the day i got it up to now, only 2 ram slots work...