Blank screen shows up while playing games

Hello guys. I have a very weird problem that when i play any game for 5~10 minutes the screen becomes white/black/green/green + black lines, and i can’t do anything but i can still hear the game and any song i was playing and i have to restart the PC. When this problem first occurred, it only occurred in games after playing for a specific amount of time but now it occur without even playing games after 3~4 hours of normal computer usage and now when i open any game i can’t even play for 5 minutes…It happens after 1~2 minutes…Some people told me it was because the PSU but i have been using the PC for more than a year now normally with no problems plus i guess if it was from the PSU the PC would completely shut down. So, i think it is from the GPU but i have no idea what’s the problem. My PC Specs are : Intel Core i3-2120 3.3GHz
AMD Radeon 7770
8 GB Ram
Litepower Thermaltake 450W
Windows 7 Ultimate 64 Bit
Samsung LED Screen 1366×768
Answer #1
check gpu temperature before and after starting the game, gpu heating can cause display corruption
Answer #2
How could i do that ? I downloaded programs like SpeedFan and Furmark but how can i see the temperature while in game ?
Answer #3
I use a Kogan TV which uses a Samsung LCD panel. I have a similar problem, the screen goes just like you said but randomly. Sometimes it happens 3 times each 5 mins, sometimes I can have the TV on for 3 hours with out it happening. I fix the problem by turning the TV/Monitor on and of and the screen refreshes looking like normal. More or less I think your problem is broken TV/Monitor, try turning the monitor on and of the next time this happens and if loads up normally you know it is a TV prob not a computer one. Other option is to try another TV/Monitor to see if you have the same prob or not. In my circumstance I have to replace the TV which I cant afford to do at the moment so I just deal with it. Hope this helps identify your prob.
Answer #4
Okey, I tried replacing the GPU with an old one and it worked without problems so i guess I have to buy a new GPU..Thank you both for the help anyway.
Answer #5
Try checking your temps first. If it overheats. Try applying good thermal paste again maybe it’ll do the job.