iMac got issues power on

When I used iMac (2010 year) turn power on from press the button. There no screen light on, no fan move speed and no running. Nothing happen! What **** this happen and has never seen this isses before.

Any you know why? Shall I need repair for iMac? I has been use it two week ago and was shut it down then leave for two week.

I hate loss everything iMac because it's just four year old and still great running no problem.

PLease advise here thanks you.