Weird problem

Hello This is a relatively new rig, bought it ~9 months ago CPU AMD Phenom II X4 Quad-Core 965 BE MB ECS A 890GX-MA HDD Samsung EcoGreen 1TB GPU Sapphire ATI PCX HD 5770 1GB GDDR5 HDMI/2DVI/ DP RAM Corsair 4GB (2x 2GB) DDR3 1333MHz, with Classic Heat Spreader CASE CoolerMaster 690 II PSU CoolerMaster Real Power 620W 80plus COOLER Cooler Master Hyper 212 Plus RR-B10-212P-GP The thing is, few months ago I had this weird combination of problems… while browsing the internet, suddenly some noise came out from the speaker, there were some really fast appearing and disappearing horizontal lines on the monitor, 5-6cm(~2inches) and the numlock from my keyboard was blinking(turning on and off). I panicked and rebooted the comp immediately and everything was fine for the frist half an hour until it started again. I panicked again and shutdown the computer. Turned off the power cable and went outside. Came back few hours later, plugged in the power cable, turned on the computer and the problem never appeared again until now. Now the problem appeared again and this time I shutdown the computer without plugging off the cable. Went outside, came back 4 hours later and the problem appeared again but only lasting several seconds and disappeared without rebooting/shuting down/plugging off cables. What is this? Why is it happening? I'm suspecting something with the power supply, a more experienced friend(almost an expert) suspects something with the electricity in my house… Any insight from the experts here is very welcome!

sounds a bit like a hardware lock up, my pc sometimes does a similar thing where all the lights flash on the keyboard before shutting down and restarting(if you don't hard re-boot first by holding in the power button) it's an overclock/heat related cpu problem for me, but i think yours may be gpu related, so first thing i'd look at is your temps for both cpu and gpu, but yes i'd think it could also be a power supply fluctuation problem. i think i'd also run a full test on your ram, see if that's locking up/has problems too.

I agree with your initial assessment and the first thing I would do if I built this machine, as part of normal troubleshooting anyway, is swap in a known good power supply - if nothing else, to eliminate power issues from the equation. However, I did not build this and it seems you did not either. And since it is less than 1 year old, it should still be under warranty - therefore, you need to call the builder now and get on record that your hardware is failing.