LAPTOP Help! I BROUGHT FROM EBAY AND NEED TO MAKE SURE ITS A GOOD LAPTOP?

I have a lenovo thinkpad edge. It starts up great and turns on but then after like 15 minutes, i will get one short beep then the screen flickers black, then after a few seconds it turns back on. The light on the side will dim(the red light on top of the I in thinkpad). Do you have any idea what this is?

There's something more than likely shorted out on the motherboard. Was it an as is sale? Can you get your money back?