Not with the power switch off but just by pressing the regular on/off button my PS3's light will turn from blue and green to red but then it will keep venting. What's wrong with it?
If you are saying that your PS3's vents are still going even though it's in standby mode. The only reason I can think of is maybe you have remote play enabled? When you have the remote play, the PS3 will keep the vent on since the machine is "somewhat" on to be able turn on through the internet with a PSP.