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Old November 7th 06, 12:47 AM posted to rec.radio.amateur.equipment
[email protected] sailtamarack@yahoo.ca is offline
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First recorded activity by RadioBanter: Sep 2006
Posts: 44
Default Dead Yaesu ft-890 Help!

Steve,

I only have the downloaded schematics to work with. I was not able to
find a free service manual download on the net so I can only make some
assumptions about circuit operation.

The schematics show the power coming in, via the molex connector, to
the PA board. There is a filter circuit consisting of some capacitors
and a large inductor. The output feeds a relay (clicks at power on)
which provides power to the rig. The relay is controlled by the front
panel switch and a transistor control circuit associated with the PTT.

One thing to try is to check the keyer switch settings on the top of
the radio. The Break In switch may be in the wrong position. Is it in
full or semi?? Try both? Is the keyer in manual?? Remove the
microphone as well in case there is a PTT problem with it.

You could try measuring voltages starting at the molex connector with
the cover off. Put the black probe to ground and trace the circuit
with the red probe. Look for loose connections, burnt traces etc.
There is a set of schematics in pdf form at http://www.kb2ljj.com


Let me know how you make out - Roger