Aiwa amplifier sound problem

[leafar]

I have my old model of Aiwa amp XA-006H,I`ve tried to fix it . No sound but relay is ticking when power on and after power off.Tested the speaker output terminal with unstable varying 50k ohms to 150 ohms resistance. Checked resistors found all ok. Changed the IC UPC1225H.Changed defective Transisor D2006 to D2005 as replacement part since its hard for me to find the D2006 in many electronics shop. Also I have checked a zener diode shorted but dont know the ratings which visibly seen thru markings 3 in the upper portion and 15 on the bottom.I decided to replaced it to 15V.Is this the reason why its not working right now? Please help me.Thank you