Hello pianopeter, I have the same amp with the same problem but only when the crossover mode switch on the front channel is set to low pass or high pass. Have'nt fixed that yet cause when I got the amp and put power to it the clip and protect lights would flash back and forth. I turned out to have 2 bad output transistors on the right front channel, I replaced them and amp works great now. Then when I was doing final testing I switched the crossover mode switch to lowpass and your problem occured. I do believe the problem is in the removable board which controls the controls the crossover and input to a point. Try moving the crossover mode switch to flat on both front and rear and let me know if amp works fine that way. I'll be working on this problem soon but would like to know if your problem changes if you move the switch to flat. Please leave me a message as soon as you find out cause this will aid in the process of me fixing problem. I am an electronics tech and buy and fix broken amps all the time so I have a really good knowledge of car amp repair. Once again let me know ASAP, Thanks

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