Hi, yes, i know, it is a common thread for this amps family but still a real problem.
I've started working on a SA-8100 and then the famous protection bulb shines again! ;-)
I tested the voltage and got :
Protection board : AWM-027, pin 16, very instable and fluctuating around 20V where it should be around 35V.
Check on the power supply board and got the same 20V on pin 19
others checks on power supply board show that except pins 16 and 17 where I found respectively 13V and -13V, all others voltages are at least 10V below the reference.
I've changed Q1 and Q2 with TIP 31C and TIP 32C respectively, no improvement.
I've checked R1 and R2, ok.
I also found around 55V at the base of Q1, where it should be 35.6V
I am blocked now and need some advices from experts to move forward ! :scratch2::scratch2:
Many thanks,
I've started working on a SA-8100 and then the famous protection bulb shines again! ;-)
I tested the voltage and got :
Protection board : AWM-027, pin 16, very instable and fluctuating around 20V where it should be around 35V.
Check on the power supply board and got the same 20V on pin 19
others checks on power supply board show that except pins 16 and 17 where I found respectively 13V and -13V, all others voltages are at least 10V below the reference.
I've changed Q1 and Q2 with TIP 31C and TIP 32C respectively, no improvement.
I've checked R1 and R2, ok.
I also found around 55V at the base of Q1, where it should be 35.6V
I am blocked now and need some advices from experts to move forward ! :scratch2::scratch2:
Many thanks,