When I press the power button computer starts, stops briefly, then starts again

[admirablefearfulkangaroo]

It is a 1 month old prebuilt case. It started to have a crashing problem few days ago. It was crashing after a mildly bump on the table it is on. Like if I put a glass a little hard on the table, computer screen freezes and I had to restart to get it working again.

Today it crashed again. When I tried to restart it kept freezing on the windows 7 logo. I kept trying and somehow it worked, but crashed again in five minutes.

Now I cant even see anything on the screen. When I try to power it up, it starts then stops then starts again. (Without me interfering) No signal to the monitor.

What should I do?

Specs:
Intel i5 650
Gt420m
I dont know the other parts, but it is a cheap computer so none of them are good.

 

[admirablefearfulkangaroo]

Found out that one of my ram sticks is faulty. I deattached it and the computer works fine.

 

[admirablefearfulkangaroo]

Found out that one of my ram sticks is faulty. I deattached it and the computer works fine.