M
Mark
Yorkville repair
The MONITOR CLIP light was on all the time.
The circuit uses an MPSA13 type Darlington with a bunch of wired or
diodes to the base. The base circuit trace runs all over the board.
There is no real pull down for the base circuit other than the
transistor input impendence which is very high. The base was being
pulled high turning the light on but none of the wired or circuits
were high. The base circuit trace itself had some leakage path the Vcc
or something. I removed the part of the trace that runs from the
transistor over to the mic input side of the board and replaced it
with a jumper wire. Problem solved.
Mark
The MONITOR CLIP light was on all the time.
The circuit uses an MPSA13 type Darlington with a bunch of wired or
diodes to the base. The base circuit trace runs all over the board.
There is no real pull down for the base circuit other than the
transistor input impendence which is very high. The base was being
pulled high turning the light on but none of the wired or circuits
were high. The base circuit trace itself had some leakage path the Vcc
or something. I removed the part of the trace that runs from the
transistor over to the mic input side of the board and replaced it
with a jumper wire. Problem solved.
Mark
