Lanzar MXA 282

[Perry Babin]

And as of right now, do you have the rest of the parts in the board and still have -rail on the output?

Is R176 within tolerance?

 

[S Merlington]

All of the parts are in the amp..

R176 measures 4.65 ohms

I have 51 volts of rail on the right channel outputs The voltage is positive rail..

 

[Perry Babin]

Post the DC voltage on all 3 legs of the 4 differential amp transistors. You may end up needing to post the voltage on virtually all of the transistors but we need to start with these.

 

[S Merlington]

what ones are the differential transistors?

 

[Perry Babin]

The 4 with their emitters connected to the 4 100 ohm resistors in the middle of the channel.

NTSHRM800 (<< ignore).

 

[S Merlington]

A970
Leg 1:-2.98
Leg 2:-4.26
Leg 3:-3.59

A970
Leg 1:-3.11
Leg 2:-52.1
Leg 3:-3.71

C2240
Leg 1:-4.27
Leg 2:-4.27
Leg 3:-3.60

C2240
Leg 1:-4.34
Leg 2:-4.33
Leg 3:-3.72

 

[Perry Babin]

Copy and paste it and add the circuit board designations.

 

[S Merlington]

Q110- A970
Leg 1:-2.98
Leg 2:-4.26
Leg 3:-3.59

Q109-A970
Leg 1:-3.11
Leg 2:-52.1
Leg 3:-3.71

Q106-C2240
Leg 1:-4.27
Leg 2:-4.27
Leg 3:-3.60

Q105-C2240
Leg 1:-4.34
Leg 2:-4.33
Leg 3:-3.72

 

[Perry Babin]

The center legs of those transistors should be near rail voltage. Follow the traces back. You likely have a bad solder connection on a jumper. Don't just resolder them. If you have a bad solder connection, you need to remove the jumper, scrape it until you have clean copper then replace it. If it's easier to use new wire, do that.