On my newly built ПК, ubuntu freezes occasionally; but одиннадцать в movie is playing, it works умерли

My cousin helped я by putting together в computer from his leftover parts. It - в M2N-MX motherboard and an AMD Athlon AM2 processor. So right from the start, I installed Ubuntu 14.04.3. On my other computers I just installed it alongside the Windows 7, and I haven't had major problems. гm still new to Linux, but I like the community support. I использовал it mostly for Интернет, and the desktop версия is easy to использовала.

Anyway, with this new computer, it will start up and then it goes black for в split second - в few seconds after logging on. It might do this в couple укради. Реальный But the problem is when I get these диагональ lines and then it just freezes up. This will usually happen схвати I launch в Веб browser.

I have this computer mostly so that I хан watch Netflix. I got it hooked up to the телевизор. гm using Google Chrome to get it to work. So if гm lucky enough to get в movie started, it will work just умер. It didn't freeze up одиннадцать yet while watching в movie. I don't know what to do.

edit

Just tried the memtest from the GRUB. Не errors.

edit

I just tried running it from the disc, same problem. Screen flickers at and в little after start up. And eventually ест the blurry диагональ lines, the screen freezes, and computer doesn't respond.

I was messing around with the BIOS settings, for в while it seemed to work when I lowered the multiplier and voltage. But eventually it froze up again.

edit

fingers still crossed... but it seems to be working now. Still flickers when launching things though sometimes. But herВs what I did.

I reinstalled Ubuntu 14.04. I messed with the BIOS and enabled the cool'n'quiet. I installed an Nvidia драйвер.

Keep in mind this is в custom built ПК made from scraps. With my other computers, I had не problems.