[ICOM] IC-756ProII CI-V DEAD!

[William J. Wickstrom]

Larry:

Thanks for the info. Applying your initial test has revealed that there is
an OPEN circuit from sleeve to (chassis) ground at the REMOTE jack. The TIP
measures ~200K. I'll be opening the rig to investigate further.

Rich:

Thanks, but the very first thing I tried was a MASTER RESET.

I'll report back when I have more information.

73

W1IK

--- On Tue, 1/1/13, William J. Wickstrom <jwickstrom at surgesound.com> wrote:

From: William J. Wickstrom <jwickstrom at surgesound.com>
Subject: [ICOM] IC-756ProII CI-V DEAD!
To: icom at mailman.qth.net
Date: Tuesday, January 1, 2013, 4:19 PM

Hello, All:

While operating SKN last night the CI-V data to/from my 'ProII quit (it was
working fine, and all works with my 'mkIIG). I have been able to determine
that the problem is indeed within the 'ProII, and NOT anywhere else in the
CI-V chain. I believe that perhaps some stray RF, or perhaps some other
spike, took out the CI-V in the 'ProII. I have the service manual (in .pdf
format), but could use some guidance as to where to start looking for
faults. Has anyone else had this kind of problem occur? Any help from this
group would be greatly appreciated!

-----------------------------
Date: Tue, 1 Jan 2013 14:46:26 -0800 (PST)
From: Larry Young <k4lxv at bellsouth.net>
To: ICOM Reflector <icom at mailman.qth.net>
Subject: Re: [ICOM] IC-756ProII CI-V DEAD!
Message-ID:
	<1357080386.76663.YahooMailClassic at web181006.mail.ne1.yahoo.com>
Content-Type: text/plain; charset=us-ascii

Bill: Here is a CI-V port test for the ProIII courtesy of John K3CT of the
ProIII Yahoo group:

1. Disconnect the power from the radio and insert a blank 1/8" plug into the
remote (CI-V) jack.

2. Measure the resistance from the plug shield to the radio frame. It should
measure less than ~1 Ohms. If it is open or resistive, replace the TDK
ferrite bead on the back of the radio board.

3. Using the blank 1/8" plug again, measure the resistance from tip to
shield. It should measure high resistance (>400 K Ohms) if not, Q3772 is
likely damaged.

4. For those that don't have the computer case and radio both connected to
ground, consider adding the connections so the computer and radio stay at
the same potential during lightning or surge events.

I suspect the ProII and ProIII CI-V circuits are the same. The Q3772 number
may be different.
Good luck,
Larry K4LXV

----------------------------------------------------------------------
Date: Wed, 02 Jan 2013 08:12:52 -0500
From: Rich Dailey <redailey1 at gmail.com>
To: ICOM Reflector <icom at mailman.qth.net>
Subject: Re: [ICOM] IC-756ProII CI-V DEAD!
Message-ID: <7.0.0.16.2.20130102081201.0aae5da0 at gmail.com>
Content-Type: text/plain; charset="us-ascii"

I always suggest a reset of the rig before investing in troubleshooting
time.

N8UX