You should NOT drive the amplifier into the clipping mode continuously. There is a possibility that you have fried your speakers or that they are the real problem. You haven't told us what you were driving, however this amp will deliver 450 Watts per side RMS at 8 ohms which means your speakers have to be rated at least that much RMS power for continuous. When speaker voice coils fry, they can wipe out amplifiers. Let us know what speakers you are using and how they are configured. This amp is going to be expensive to repair I can tell by looking at the schematic: Here is the schematic:
Scroll down to "get manual" and click to download it. IGNORE other download links.
This amp has circuits to boost the power supplies to the amps to handle the peaks. It is rather complex but the schematics are complete and have good explanations... some of the best I have seen. There are going to be a lot of destroyed components and great care has to be used after repair to "cold start" the unit to make sure nothing else is bad or it will blow up again. Most people do NOT have trouble with the QSC amps... so do tell me what speakers you are using and how they are configured so we can verify the design is correct. This amp is rated for 8 ohms so USUALLY only ONE speaker can be connected per side... and finding an 8 ohm speaker that can take 450 watts continuous RMS isn't easy. People fall for the advertising claiming "Peak" and "Program" power which are FAKE advertising... ONLY use continuous RMS power when sizing amps and speakers. There are MANY ways to cook out equipment... One is to boost the bass or the treble way up. Another is to NOT use balanced interconnect lines between mixers and your amps. Yet another is to NOT power ALL interconnected equipment from a single receptacle or power conditioning module. Please describe your setup further so I can help you more!