GS 600 Gaming series Psu is shutting down PC

Hi i am from india and bought a Corsair Gs600 gaming series Psu from lynx india.com in 2011.My problem is my PC is shutting down randomdly while surfing the net or While playing games.Before shutting down i do get some beeps and its justs shut downs without any error message or BSOD.I checked each part and narrowed it down to the psu and motherboard.My PC works fine after a Cmos reset with jumper and when i turn my room A/C on at night.During the day when i turn off the Ac and surf then net or play a movie file it shut downs randomly.



Is the Psu heating up and shutting down other components? and what can i do to fix it?