The power supply voltage is 11.88 volts.
DC voltage at terminals Q319:
between common ground and Q3190:
1. 7.72
2. drops to 0V
3. 8.2
between left speaker:
1. drops to 0V
2. 4,51V
3.Drops to 0V
The resistance between the negative terminals of the speaker and the primary mass is infinity.
DC voltage at terminals Q319:
between common ground and Q3190:
1. 7.72
2. drops to 0V
3. 8.2
between left speaker:
1. drops to 0V
2. 4,51V
3.Drops to 0V
The resistance between the negative terminals of the speaker and the primary mass is infinity.
The supply voltage is 14.4 volts.
DC voltage at terminals Q319 between common ground and Q319:
1. 9.74 V
2. ≈ 0 V
3. 10.23 V
After installing the jumper between the negative terminals of the speaker and the primary ground, the DC voltage at terminals Q319 between the negative terminal of the speakers and Q319:
1. 9.74 V
2. -6.6 V
3. 10.23 V
DC voltage at terminals Q319 between common ground and Q319:
1. 9.74 V
2. ≈ 0 V
3. 10.23 V
After installing the jumper between the negative terminals of the speaker and the primary ground, the DC voltage at terminals Q319 between the negative terminal of the speakers and Q319:
1. 9.74 V
2. -6.6 V
3. 10.23 V
Yes, I tried different modes for both channels. I have doubts about the two resistors R353(6,8K), R360(22 K). When measured without soldering them out of the board, they have the following readings:
R353 - 5.15
R360 - 7.9K
Do I need to drink them out to measure them correctly?
R353 - 5.15
R360 - 7.9K
Do I need to drink them out to measure them correctly?
With the muting transistors out of the circuit, if there is no audio, the problem is in the audio path. You'll have to trace it from the input RCA jacks to the driver ICs to see where it's being lost.
You can pull those and check them later if you still have issues when the three transistors are soldered back into the circuit.
You can pull those and check them later if you still have issues when the three transistors are soldered back into the circuit.
Was it open/shorted? It's a darlington so it may seem defective if you're checking with a meter.
https://alltransistors.com/adv/pdfdatasheet_rohm/2sb1076m_2sb1239.pdf
https://alltransistors.com/adv/pdfdatasheet_rohm/2sb1076m_2sb1239.pdf
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