Windows 10: Monitor keeps not finding a input signal and pc "crashes" while gaming

My Situation:Since two days I am having a problem I have never had before.When I play certain games and sometimes even on the desktop, my screen turns black, saying it does not have an input source anymore and it stays that when. When I play a game I still hear the sound but it glitches out and continues playing even when it should be finished already. In online games I get even kicked out of lobbies.The problem is irregularly, it happened 2 minutes from starting the pc to 15 minutes to even 6 hours, so I cannot pinpoint anything from that.It happened to me that 2 times in between trying to fi

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Monitor - No Input Signal

So you are suggesting that in the event this cable goes for a six, I try out the HDMI port? Seems quite a tenable suggestion - I never thought of that!

 

all games crash!

I suggest you run rthdribl > http://www.daionet.gr.jp/~masa/archives/rthdribl_1_2.zip
Increase the window size step by step and watch your vga temps permanently.
What happens?
If it crashes, run at stock speeds as suggested before and retry.

P.S.: When your system locks, does the display signal turn off after a time?
Stuttering sound or no sound at all when freezing?
What X1800XT model do you own exactly?

 

I've got the old "No input signal" .....Help!

I don't see the need to because I know the tv I'm using as my monitor works fine with another PC hooked up to it using the same HDMI port and it works perfect on that PC.

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Ok as per your suggestion I hooked it up to another 27" monitor I have and it says the same "No input signal" on that monitor.