Yamaha RX-V765 Amplifier Issue

[irobot]

Yamaha RX-V765 7.1 Channel Home Theater Receiver

After replacing Q1055A and Q1055C (outputs) and emitter resistor R1153:

-1.5V DC on speaker output, SL channel. Although the unit works, it should be near zero. Not comfortable leaving it this way.

B+ and B- are where they should be at all points.

I'm at a loss because I've checked every component and taken other measurements using good channels as reference.

Voltages on other channels are just about spot on to what schema shows.

I replaced Q1041, Q1048, C1034 with no change.

Notes: Q1020, Q1027, Q1034 are for bias. Q1062 is a tap-off point for protect signal. Q1027 is physically attached to heatsink as temperature "sensor".

UPDATE 10/04/2024: Fixed. Replaced Q1011 and Q1012. Although checked out OK in and out of circuit, these must have been breaking down with power applied.

[David_AVD]

There will likely be a dead transistor or resistor somewhere just before the output transistors.

[suntime]

Hi,

Check Q1020 & Q1011.