Hi, i have a Philips HTS 9800 entertainment system for the past 3 years and it was working fine up until last week. I had it playing full blast for nearly a whole weekend and since then it only works fine on low volumes but if i try to bring the volume past half way it gets distorted and wont go any louder. The speakers are all fine, i have tested them on another system so I think its the amp. I opened it up earlier today to see if I could see any bulging/damaged capacitors inside but they all look to be ok. Has anyone ever come across this type of problem before? What should I be looking out...