Re: Amplifier Problem - Revised Schematic

"EADGBE"  wrote ...
> In the interest of clarification, I have added some information to the
> schematic of the tape deck headphone amp that I'm having problems
> with.
>
> Some circuit paths are now labeled:
>
> http://i240.photobucket.com/albums/ff58/eadgbe123/amplifier-1.jpg
>
> As always, the points at which voltage readings are marked with a star
> are NOT producing the voltage indicated.  The +7V location is
> measuring 131mV instead.  The other two points where a star is
> indicated are measuring between 20mV and 30mV (fluctuating slightly).
>
> I am starting to think that a circuit OUTSIDE of this circuit might be
> at fault, because NOTHING inside of this circuit seems to be
> faulty...but the darn thing still WILL NOT work.

Can't see what parts external to the circuit shown could
cause any of your symptoms. The input and output are
decoupled with capacitors.  Furthermore, you confirm
that the internal, DC side of the input and output are
at the prescribed voltage. You have also confirmed that
the supply voltage is OK. There is nothing else externally
that could affect the circuit.  I am assuming that the
node at the lower left corner finds its way back to
ground somewhere.

The question remains why the collector of Q205 is at
131mV rather than the predicted 7V.  Q205 is simply
not conducting and that is causing all the rest of the
symptoms.

One of the marvelous things about stereo is that you've
got two identical channels. So you have a good one to
compare it to.

What is the base voltage of Q205 on the working side?
And what is it on your broken side?