I just installed another Motherboard in this Optiplex 755 Small Form Factor PC and the error lights come on for a few seconds and the unit powers off. The lights are #1-Solid Green, #2-Off, #3-Solid Green, #4-Solid Green. The Power Light stays on until the unit powers completly off. Then it trys to restart.

 I think my processor is ok as I just bought it recently. It is an Intel  E6550. According to the spec sheet this should be one of the correct processors for this board. Any suggestions would be greatly appreciated.

Thank you