After few repairs, I keep at home, I listen one or two weeks ... and the sound shot down after 15 seconds, I hear the relay opens. If I turn off and turn it on, the relay closes and I hear music for 15 seconds, and so on. It is the same if I start in A or in B mode. I try with headphones without speakers, it is the same.
I found this Yamaha CA1000 in the garbage with a turntable.
In the beginning, when I found it, the amp was not working. The A/B switch was cleaned, the two outside microswitches changed, the back card was cleaned and resoldered. The amp was badly repaired in the past, with transistor installed in the wrong way, bad soldering everywhere on new low-cost components, wrong power transistor replaced, few ceramic resistance was changed.
I found this Yamaha CA1000 in the garbage with a turntable.
In the beginning, when I found it, the amp was not working. The A/B switch was cleaned, the two outside microswitches changed, the back card was cleaned and resoldered. The amp was badly repaired in the past, with transistor installed in the wrong way, bad soldering everywhere on new low-cost components, wrong power transistor replaced, few ceramic resistance was changed.
Thank you JayCee
I tested the voltage of both main cards. The right one was a little bit off. The 15 volts was a 15.9, Class B was at 0,00, Class A was at 0,2, and the 0 volt was at 1.6, I could only set it to 1,0 but it was enough, the protection relay stops to cut off, the music plays.
The right card LC65140 was badly modified, the Tr 610 was changed for a different type of transistor B595 ?. I don't know if it is right?
I tested the voltage of both main cards. The right one was a little bit off. The 15 volts was a 15.9, Class B was at 0,00, Class A was at 0,2, and the 0 volt was at 1.6, I could only set it to 1,0 but it was enough, the protection relay stops to cut off, the music plays.
The right card LC65140 was badly modified, the Tr 610 was changed for a different type of transistor B595 ?. I don't know if it is right?
At the end I saw a little white wire unsold on the card. I reset the 4 voltages and that's it. The card was serviced many times, at the end the wires was not soldered through the card but on the soldering.