EADGBE wrote in news:7a5f62ce-00ec-4fac-84f3-
:

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/f...mplifier-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.

You do NOT indicate the voltage on Q205's base, also Q204's collector.

If it is 11.9, then Q204 is not conducting and Q205 has no forward bias,
will not conduct, and all other bad values follow from there.

Since the OTHER voltages around Q204 are correct, the collector of Q204
should be LOWER than the 11.9 rail by half a volt or so.
It should thus be 11.4 on Q204 collector and Q205 base.

If it isn't, then Q204 is probably bad, open on the base/collector
junction.




--
bz

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

remove ch100-5 to avoid spam trap