OptiPlex 7060 turns on and off in the loop with white light on

Hi, 
I have an OptiPlex 7060 that worked without a glitch for years. Today, I tried to turn it on and it did not start. I checked if the power cable is well connected and I have a green light on the back indicating that the computer is receiving the power. The moment I connect the cable, there is a single blink of oragne light and it turns to white. It stays in that state for about 30 seconds and turns off by itself and repeats the cycle for as long as the power cable is connected. 
It does not recognize any displays at any stage. I dusted the insides and removed the RAMs and tried to put them back one by one but that did nto help. 
If you have an idea why would this be happening and how can I resolve this issue, it would be very apprechiated.