Mtx ta92001 distorted output.

[kfx5050]

I haven't yet. I was tracing the Trace from the large resistor to see where the 22 volts is coming from. Be for the large resistor I geting 108 DC volt. After the resistor. I'm getting 22 volts. The same volt at the speaker terminal. After the large resistor it goes to the pin of the op-couplers

 

[Perry Babin]

Does the output voltage still drop to 0v is you connect a speaker?

 

[kfx5050]

No. When I connect a speaker to push all the way out. What would cause my rail voltage to be uneven between negative and positive rail voltage.

 

[Perry Babin]

Does it do this with R4111 out of the circuit?

 

[kfx5050]

Yes. I was tracing the voltage leak.I remove the capacitor by the inductors and this is what I found underneath it

 

[kfx5050]

Corrosion under this capacitor. I'm gona replace both capacitor to be on the safe side none of mosfets are in and I was still getting 18 volts DC to the speaker terminal.

 

[kfx5050]

The collector of the PZTA56 goes to the negative low-voltage power supply. It's the same supply that feeds the op-amps.

are both Transistors this part number [PZTA56]?

I have fought these components to be fail.
R4039
R4113
R4011
R4013
R4108
C161
C181

 

[kfx5050]

Does anybody know where does pin 1 of the N5534 go? one closest to the rail caps . The pad lift it up.

 

[Perry Babin]

Is it visible in any of the photos posted in this thread?

 

[kfx5050]

It looks as if it doesn't go to anything as far I can see on the photos.

 

[Perry Babin]

You're probably right. Pins 1, 5 and 8 are optional.

 

[kfx5050]

Amp is up and running now. there was a short in the layer of the bord by op-amp.

 

[Perry Babin]

I saw something similar in another MTX amp but in a different location. It had to be drilled out.

 

[kfx5050]

wow. i have other mtx ta92001 i am working on and in the same similar area{left bottom of amp facing the sub-woofer output connection} the four smd cap. c420 are burnt not shore how this happen. i won this in a auction.