[ICOM] IC-756PROIII No Transmit

[Stephen Budensiek]

Hello,
   I have an 756 Pro, got it used in about 1997.   Worked flawlessly until
about a month ago.   Run lot of RTTY, turned it off one evening after some
Qso's, all was working perfectly.   Turned it on the next morning, maybe 5
watts out, very unstable.   Put a note out here, then went to work on it as
I'm a engineering tech, and found the driver 2SC1972's bad.  One was shorted
Collector to Base, forget what the other transistors fault mode was.
Shorting Collector to Base took out a 1 ohm chip resistor also, so replaced
it with the transistors.   It has worked flawlessly since.  I never leave
the qth without the antenna's disconnected, everything is disconnected at
the faintest sign of lightening, no monitor antennas connected, only ant 1
and 2 for 6m and HF.   I afterward got notes from the Icom group of several
others experiencing the same problem, seems like too many 756 Pro's have
this problem.

73's de Stephen, K0SD

*********************************************

On Mon, Mar 23, 2009 at 6:36 PM, Alan Zack <k7acz at cox.net> wrote:

> I turned on my IC-756PROIII this morning and found no transmit on any band.
> It has been working fine. When attempting to transmit on RTTY or CW there is
> no carrier, no power out shown on the Transceivers PO meter or an external
> meter. The red TX LED light comes on and the fan speeds up but no power out.
> On SSB there is no power out on voice peaks, no ALC readings but the COMP
> meter does show a small deflection on SSB on voice peaks. Receive is normal.
>
> I did the CPU reset with no help.
>
> I disconnected the 756PROIII from the power supply and antenna and
> connected my back up IC-746 to the same antenna and power supply
> connections. The IC-746 works FB telling me the power supply or antenna are
> not the problem.
>
> There is no computer interfaces, etc, involved. Just the basic power
> supply, antenna, and speaker connections.
>
> Does the 756PROIII suffer from the loss of power out problems that the
> IC-746PRO did?
>
> Any suggestions before I box it up and send it to Icom? It was ordered on
> Nov 26, 2008 and shipped on Dec 2, 2008 from HRO Anaheim so is still under
> warranty.
> _______________________________________________________
> Alan Zack
> Amateur Radio Station K7ACZ
> Las Vegas, Nevada, USA
> Delta Rocket Quality Engineer, The Boeing Company, Retired
> Aviation Chief Warrant Officer,  U.S. Coast Guard, Retired
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