My Dell T5820 Precission isnt booting up...

My Dell T5820 Precission isnt booting up not even the front panel lights just the fans are running when i press the button next to the power cord? 
the last time i checked from Dell i dont think Dell indian is any good in fixing this issue and moreover they made the problem worse.

now i am trying to fix it myself, troubshooting any help would be appriciated.