I was given an Emachine Model T1140. I plug it in and press but on switch. It didn't start but instead I noticed some sparks from the power supply. I assumed that it went bad so I bought a new power supply and installed. It started fine and bootup perfectly, but after about 2 minutes it shutdown by itself. I pressed the on switch but it didn't respond. I put the computer in the trunk of my car and took it to work. There I talked with the one of the IT guys but he coundn't figure out what was going on with it. I decided to plug it in again and it worked for 12 seconds after getting to the desktop. It then reboot by itself and after another 8 seconds it rebooted a second time. Finaly after 31 seconds it shutdown by itself and it does not respond to the switch. HELP!!!... does anyone have an idea what's going on? Any suggestions will be appreciated.