Strange problem with pc crashing during games

I've overclocked my E8400 to 3.6 with mem on a divider running at 800mhz. Recently ive started having a problem where it doesnt matter what game i am on but the screen will go off and not recognise any input and then few seconds later the pc crashes (sound still plays for ten seconds or so and then stops)

This is the weird part that i cant get my head around.. When i turn my monitor off all my fans turns off aswell, turn it back on all my fans inside my case start running again..how is this connected?

If i go back to default and 3ghz i dont get this problem but still..why has it only started recently?

Recent changes are from a samsung 22" screen to a 24" screen from 1680*1050 to 1900*1200 res..Thats the only change..maybe the extra power required to run at that res is causing that problem?

 

I think it's due to your cpu being unstable to overheating.

 

how do you explain the monitor altering all the fans when turning it on/off? Thats the part i cant get my head round

 

You really haven't provided any info to help diagnose the problem.

I would say it is overheating, either the CPU or GPU (Video Card) and causing the system to crash. Although it may not have happened 3-6 months ago, normal useage, dust build up, TIM degradation, etc etc can and will allow this to occur.

Info that would really help:
MOBO:
(BIOS Ver# as well)
CPU:
(VID:, current vCore, baseline temps in OS idle/load)
RAM:
(ratio to cpu, e.g. FSBRAM)
PSU:

Furthermore a pic says a thousand words.

Your problem seems painfully obvious to me (GPU is overheating) but I need some more info and then I'll give you a nice solution.

 

You really haven't provided any info to help diagnose the problem.

I would say it is overheating, either the CPU or GPU (Video Card) and causing the system to crash. Although it may not have happened 3-6 months ago, normal useage, dust build up, TIM degradation, etc etc can and will allow this to occur.

Info that would really help:
MOBO:
(BIOS Ver# as well)
CPU:
(VID:, current vCore, baseline temps in OS idle/load)
RAM:
(ratio to cpu, e.g. FSBRAM)
PSU:

Furthermore a pic says a thousand words.

Your problem seems painfully obvious to me (GPU is overheating) but I need some more info and then I'll give you a nice solution.