I installed a new cpu in my girlfriends computer because it was shutting down, now getting same results. I took the cpu out and turned the computer on and power stayed on, little confused about this situation. Computer has new MoBo and RAM, now working on updating CPU with no success. any suggestions?Did you remember to apply thermal paste ? ?
Important Instructions
Are all power leads hooked up properly ? ?
All fans spinning and OPERATIONAL ? ?

You haven't provided very many details for this little dilemna...I am very "Green" when it comes to computers so I apologize for not providing better information. Basically what I have done is change the CPU, the OLD CPU was getting hot and overheating. We decided to change the Motherboard, CPU, Fan and heat sink. I can get the computer to come on but only for a few seconds before it starts to make a siren sound. I INVESTIGATED this situation and discovered that maybe we had a overheating problem so CHECKED the fan and it is working and all connections are good on EVERYTHING. I removed the CPU and turned on the computer and the dang thing stays on, does not shut off but of course does nothing. Could I have a bad CPU? I also changed the RAM so that it would be new also.

THANKSClick on the link provided above titled Important Instructions...