Dell PowerEdge 2950 Not Booting

I have a Dell PowerEdge 2950 and it has been sitting in storage for three years. Now yesterday I pulled it out to use for hosting local game servers so that me and my brother can play on a custom game server only for us. On the first boot it was fine although it spit out a lot of error massages. I thought "oh well it still works and i can fix it later. But one of the Memory sticks was dying, so I figured ill take out that stick and another stick so that it could not spit out those codes. but when i was finished it wouldn't power on at all. The only sign of life is when you put it in identify mode. so i reseated the ram and power supply and it booted right up.  so i wanted to hook it up to Ethernet. i grab a network switch plug it all in and not it wont turn on at all again. But there is more. I did everything i just did again but now it powers on and the fans are spinning but the hard drive are not doing anything and there is nothing on the monitor that i hooked up. pls help 

Thank You,

Jarek