No signal when gaming after upgrading pc

[TobyVanhaecke]

I've recently got a i7-3770 in my pc after upgrading from an i5-3330s and I also bought another stick of 8GB DDR3 and since doing so I haven't been able to game for longer than a few minutes because of getting no signal on my monitor, I was wondering if anyone knew any possible causes for this,
Thanks

My pc specs:
I7-3770
GTX 970 4GB
1TB HDD
16GB RAM
Unbranded 500w PSU
And a dell optiplex motherboard

 

[somesh101]

could you have bent pins on mother board?
and use cpuz and gpu z to monitor hardware like temprature and other stuff