Sony XM-1004gx

[mike49504]

Ok got 3 out of 4 channels working. Front right channel is dead.

I have both + - regulated voltages on all op amps on the cross over board. I tryed all switches and pots.

I checked for signal on outputs its saying i have ouput on the speakers terminals for both channels but right channel is dead when a speaker is connected

Any ideas?

 

[Perry Babin]

Feed signal to both front channels. Do you have audio on pins 1 and 7 of IC801?

If so, do you have audio on pins 1 and 7 of IC805?

 

[mike49504]

I have audio on pins 1 and 7 of IC801

No signal on pins 1 and 7 of IC805

 

[Perry Babin]

Those are for the front channels. If one front channel is working, you should have signal on at least one of them.

 

[mike49504]

front left is working. Front right is still dead IC805 no signal on pin1 or pin 7

I checked on the opamp for the rear channels i do have signal on both pins of that op-amp. So i know my scope is set up right.

Bad op-amp?

 

[Perry Babin]

Drive a signal into the front channels.

Do you have signal on both ends of R101?

Do you have signal on both ends of R201?

 

[mike49504]

i have signal on both sides of 101 and 201

 

[Perry Babin]

Post the DC voltage on all 8 pins of IC801.

Also note which pins of IC801 have signal on them.

 

[mike49504]

IC 801
1:0
2:0
3:0
4:-14.54
5:0
6:0
7:0
8:14.65


Its showing signal on pins 1,2,3,5,6,7

 

[Perry Babin]

Didn't you just tell me that there was no signal on pins 1 and 7?

 

[mike49504]

Ic801 has signal on the pins.

IC 805 has no signal on any of the pins

 

[Perry Babin]

Do you have audio on any op-amp on the crossover board?

If not, find the two pins on the main board that have audio (going to the crossover board). Do you have audio on those same two pins on the crossover board?

 

[mike49504]

Ok i have audio signal on the crossover boards on all op-amps pins 1 and 7

Its showing i have audio signal on both positive and negative terminals of the right channel.

But right channel does no produce sound even know with the scope its saying i have signal on both positive and negative terminals on that channel.


Left front channel plays fine shows signal on the positive terminal and deflects on the negative terminal.

But the right shows signal on both positive and negative

 

[Perry Babin]

The right positive speaker terminal has a broken connection.