Why does my Marantz nr1403 overheat after some minutes of volume raise

I have a Marantz NR1403 AVR system, my problem is that it overheats and turns off showing red blinking light in front of it when the volume is turned up a bit high within few minutes. I began to notice this soon after I changed the blown power ic which had 66 KHz switching frequency with similar power ic with 132 Khz switching frequency. Please, what is responsible? I also noticed that one channel of the 5 channels does not sound. I’m confused, can someone help solve this problem? I love this Marantz.