|I would go back in your desktop tower and reseat the memory. Take it out and make sure you put it correctly without too much force, you should hear a click noise. The two brackets on each side of the ram, should securely hold down the memory.|
This may be a power supply issue, but it could be other things as well. I recommend to go to bestbuy or any computer store, even online, and pick up a power supply tester and test your power supply, before you go any step further. I would not recommend yet giving your computer to a repair shop ( if it is not under warranty) as they would charge you couple of hundred dollars over a simple fix.
Check the power supply to see if has any life in it.
Did you take out the cpu metal heatsink as well?
I suspect its a power supply. I would just test it before your do anything.
Good luck and let us know the status.