No idea. This is literally the first instance I've ever seen of somebody doing this. What exactly heppened to this amplifier? Disease history🙂?
The VAS transistor may be dead as well
This is the one connected to the differential input transistor pair.
Check VAS stage power supply voltages.
This is the one connected to the differential input transistor pair.
Check VAS stage power supply voltages.
I got this amplifier without output transistors, the relay does not turn on.
I checked all capacitors, transistors, resistances with a tester.
they are all within the normal range.
but it doesn't work.
I suspect dual transistors, because on one the voltage almost matches the circuit and on the second it does not, although they pass the test on my tester
I checked all capacitors, transistors, resistances with a tester.
they are all within the normal range.
but it doesn't work.
I suspect dual transistors, because on one the voltage almost matches the circuit and on the second it does not, although they pass the test on my tester
There is voltages of two dual transistors on both channels.
on the left are measurements in the amplifier.
after the point service manual values
Q1.
+8v. 0v
-45.6. -47v
+8.7. 0.6v
-43.4. -47v
+0.1. 0v
Q2.
1.5v. 0v
-45.6v. -47v
+2.2v. 0.6v
-43.4v. -47v
0v. 0v
on the left are measurements in the amplifier.
after the point service manual values
Q1.
+8v. 0v
-45.6. -47v
+8.7. 0.6v
-43.4. -47v
+0.1. 0v
Q2.
1.5v. 0v
-45.6v. -47v
+2.2v. 0.6v
-43.4v. -47v
0v. 0v
i replaced the dual transistors with pairs of 2sc1845 B com and 2SA992 E com,but it got worse, a large negative voltage on the Е and B of 4 output transistors
I remind you that I did a great job of checking all the capacitors, resistances, diodes and transistors by first dropping them or raising one leg
Оnly two small capacitors C9 and C10 did not pass the test but I think this is due to their small capacitance 5p.
I tried the same capacitor from another board and it also didn't work on my tester.
Еven if it is closed or open, what harm can it do
I tried the same capacitor from another board and it also didn't work on my tester.
Еven if it is closed or open, what harm can it do
all burnt resistors were replaced. someone replaced the transistors on this amplifier as in this picture
Help me please.
I'm already starting to go crazy with this amplifier, I dreamed about it at night😅😅😅😅😅
I'm already starting to go crazy with this amplifier, I dreamed about it at night😅😅😅😅😅
I already wanted to quit everything and use it as a preamplifier, but some kind of force forces me to reanimate it all the time