All four LED Indicators are amber color

My PC was working fine until suddenly it shut down and didn't turn on,

PROBLEMS :-

• Power LED Blinks orange and goes to the normal color (GREEN) 
• Motherboard LED is also orange
• LED Indicators are also orange (A B C D)
• No Beeps
• No Display

POSITIVES :-

• Once while i was trying to repair it, My PC started working..., so i disconnected it from my workbench and replaced it in my desk, but now it doesn't Turn ON.

Please help me with this situation, most of the articles said that the MOBO is gone... I wanted to confirm it from Dell Community as well..

THANK YOU.