Please tell me the nominal value of the ZD5 zener diode

Hello, at the beginning, the 220 Ohm resistor (standard situation) and the 12V stabilizer were burnt. After replacement, it turned out that the sound amplifier also burned out. After replacing it, everything worked,
BUT THERE IS A DEFECT:
1. When turning the volume knob to the minimum, the power supply is rebooted (I send the signal via bluetooth). Through aux, the same situation.
2.
The same situation occurs when I press pause on the phone from which I send the signal.

The main voltage of 30V drops to 8-9V, due to PWM
After the automatic reboot of the...