GX-30R amplifier, one of the 100 ohms resistors always got burned

the first problem with this amplifier is turning off for a period of time and turn on again, so i replace the ic and the burned resistor, the problem was solve but the sound output is distordid, i already replaced IC, and two 12v zener diode, But still the 100 ohms resistor get burned, what could be the Main problem?
and there's no input.
Thanks for the help.
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