"William R. Walsh" wrote in message
...
Hi!

Twice I had asked what the function of the cap was, and
twice you had not replied.

I am sorry about that. I must have missed seeing it.

I assumed that as you had the service manual, and were engaged
in fault finding to component level, that you would have sufficient
understanding of circuit design to be able to just look at the cap on
the schematic, and determine its function without a second
thought.

You could say that. But I'm still *very* much in the learning phase.

OK, that's fair enough. At least we now have an idea of your capabilities.
When Teac asked you to check for DC offset, they were referring to a
standing DC component at the power amplifier midpoint. This is at the
junction of 7R43 / 45 for one channel, and 7R44 / 46 for the other channel.
The voltage with respect to chassis measured at this midpoint, should be
zero. Any positive or negative standing voltage at this point, is termed a
"DC offset". If large enough, it could be damaging to a loudspeaker, so for
this reason, there is circuitry to sense any offset, and if there is one,
block a relay from operating. This relay is normally in series with the
speaker feeds. As you are hearing some hum through one channel, this would
suggest that the relay is closing (can you hear it close after a short delay
from switching on ?) and if it is, that might suggest that there was no DC
offset . But, if the protection circuit was not working correctly, it might
just allow the relay to close with an offset present. As 7C27 is in inverse
series with 7C26, I would be inclined to replace them as a pair. Your first
move though, would be to check if an offset is present on either channel.

Arfa