i have thoroughly cleaned out all fans and the psu due a slight problem i have....when playing any games im turned off by the comp...temp sensors show no high temp....i have a ati radeon 9880 pro with updated drivers..i gig of ram and i am running an athlon 2600 xp processor..os is xp...when it boots me totally everything is switched off but lights on case stay on and the digital readings for cpu and hard drive flash...my psu is a 550 watt q-tec and its about a year old..or nearly..help would be great guys...many thx in advance