punch 200s problems

[bdgf2004]

with them in the circuit i show 297 ohm on each one.

 

[Perry Babin]

What is the DC voltage on each of the legs of Q111?

Place the black meter probe on the amplifier's ground terminal. Place the red meter probe on the point where you need to measure the voltage.

 

[bdgf2004]

B=-17.66
C=-1.826
E=-18.16

 

[Perry Babin]

What's the rail voltage and the voltage across R146?

 

[bdgf2004]

The rail voltage is 25.20v and -26.00v=51.20v.
The voltage across R146 is 0.657v.

 

[Perry Babin]

Is this the only problem with this channel?

Is the other channel producing clean audio?

 

[bdgf2004]

this channel is producing clean audio, just Q111 gets hot. the other channel has no bottom half.

 

[Perry Babin]

Lift the diode for the protection circuit for the low side FETs in the channel that has no bottom. Does that allow it to produce the bottom of the signal?

 

[bdgf2004]

Yes lifting D204 allows the channel to produce a clean signal

 

[bdgf2004]

i found that Q216 was bad so i replaced it and reinstalled D204 and both my channels are pruducing clean audio. i will try it with a load next.