[ICOM] IC-2720H problems

[pss at tecinfo.com]

John,
My 2720 has been a flawless radio in the year and a half that I've
owned it but I did have a similar problem on a brand "K" dual band
rig a few years ago. When turned off it would still emit a hissing
sound from the speaker that, like yours, would not go away until power
was removed. It also would get hot while hissing. A quick check
indicated that it was transmitting while off as well as hissing. Cliff
put me on the right track by telling me that even though the control
head was turning off the main radio body was not. True to his word,
I found a switching transistor in the main body that switched 8 volts
to several circuits had shorted in turn keeping those circuits "on"
even though the control head was off. In that radio the transistor was
a small surface mount piece that was mounted on the underside of the
circuit board. It required a complete disassembly of the rig to get to
it. I hope your repair is easier. 73
Paul, N5PS

> My *IC-2720H has some problems.
> When I turn the radio off I hear a loud squeal from the speaker, The
> squeal will continue
> until the power cable is disconnected.
>
> I have removed all connections from the radio and tried a different
> power supply and still the same
> thing.
>
> Any idea's??
>
> Thanks de John KØCQW
>
> *
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