Alienware Aurora R3 two beeps

Hello,

Specs:

I7 2600k processor

4x4gb ram

2x ATI Radeon 6950s

I purchased my machine in 2011, it's been really good to me until recent. I've been doing a lot of gaming on it the past few days plus it's been hot. I was getting low fps in games, and very high core temperatures 70 and sometimes as high as 90. So I just shut the system down and cleaned all the dust out. Powered back up same issue. So I pulled the heat sync off and replaced the thermal paste... Went to turn it back on now I'm getting the two beeps no post. I've tried everything swapping out ram, tried every single ram port and every single stick individually, reset CMOS, removed the motherboard cleaned it off thoroughly with 99% iso.. put it all back together 3 times now.. lol same issue.. no post two beeps. Tested the ram on another rig, they worked fine.

Thinking I will need a new Mobo :(

I'm out of ideas, anyone have any thoughts?

Thanks!