ic 229h no modulation, NOT Mike related ( tried 3 Mics! ) suspect radio it self.

[KJ6OJL]

Looking for suggestions on where to start Trouble shooting a IC 229H Unit,
This was a unit given to me from a very good friend W5KTT. He used the unit without a
traditional Hand mic, So the mic was new from when he got the radio. I have 3 different Mics I have tried.
Hm-14 Two others, I am not with radio/mics at the moment.

But Three different mics two were obtained as "known good" and With all three tried and a HT used as a way to verify.
I am getting a full quieting carrier which I had already had but No modulation as confirmed before. (Thanks TO WB2WIK)
As of now I am thinking NON mic issue
with mic's them selves. But looking for input on where to start checking out the radio.
anyone got a flow chart of suggested trouble shooting steps?, Or Home Brew documented repair project?.


P.S. It did take a 2 foot drop some time ago.
Backlight worked after tapping radio.
So other ideas of what could have worked loose appreciated too
Thanks everyone.
I look forward to repairing this unit
73
KJ6OJL
Don

[KO6WB]

The best spot to look is at the MIC-AMP UNIT. It's in the service manual and you can get it here; http://www.ko4bb.com/Manuals/ICOM/IC...ice_Manual.pdf.
If you are not getting an input to the section then nothing will happen. If you are getting a signal to it and the output is good then it's after the MIC-AMP UNIT. There is a deviation adjust R12 but do not touch this until you confirm the MIC-AMP UNIT is working properly.
Hope this helps
73
Gary

P.S. Don....A proper repair action is a 3 to 6 foot drop. That's why your rig didn't work not enough G forces. Just kidding of course.

[KA1MDA]

First thing I would do is check to make sure the 8V DC bias voltage is present at the radio's mic connector. Without the 8 volt bias voltage for the mic element, there will be no audio. Be very careful measuring the voltage! From what I understand, it's extremely easy to damage the 8 volt regulator by accidentally shorting the 8 VDC pin to ground.

Tom

[KJ6OJL]

Thanks for the input hope to have the time to crack the shell tonight and take a look.
Will post update if there is anything discovered or suprises in the unit

[KJ6OJL]

Ok anyone have a trick tip idea of getting the microphone nut off to get the face plate off??
73
kj6ojl
Don

[KJ6OJL]

I have never seen a castle nut this tight and locked in place have tried tapping it and everything.
No idea if they used lock tight or just over cranked it!

[KJ6OJL]

Ok, as of now wd40 a qtip, got the nut off.
I checked all connections still same issue with no modulation have not had ability to test points mentioned yet. Also need to research which exact point for the probes.

[W9GB]

P.S. It did take a 2 foot drop some time ago.
Backlight worked after tapping radio.

Don,

Well, you have admitted it has been dropped (G-shock), which is not good.
Cracked boards, fractures to circuit board traces or even broken solder joints (SMT) possible.

START, with the IC-229 Service Manual
http://www.ko4bb.com/Manuals/ICOM/IC...ice_Manual.pdf

Unless you have some experience, tools, some basic test equipment,
and GOOD magnifiers to see ... Modern radios are not consumer serviceable.

[KJ6OJL]

Yes, never good G-shock, and I have a light up magnifier on a arm, Just got my DMM from other location.
I am thinking possible on the solder joints.
I have not been able to get my iPod to load the video I took of demonstrating the issue and paste a link here.
Will try try again tonight as I am on a friends desktop.
I used to do some board level work YEARS ago, Honestly I haven't used it and need to refresh and get back what knowledge I used
to have.
I used to do laptop screens take em out level by level and replace CCRT's on em, but that was a long time ago.
out of practice

Don,

Well, you have admitted it has been dropped (G-shock), which is not good.
Cracked boards, fractures to circuit board traces or even broken solder joints (SMT) possible.

START, with the IC-229 Service Manual
http://www.ko4bb.com/Manuals/ICOM/IC...ice_Manual.pdf

Unless you have some experience, tools, some basic test equipment,
and GOOD magnifiers to see ... Modern radios are not consumer serviceable.

[KJ6OJL]

Ok, finally iPod was able to publish my video to you tube.
Here is the failed rig..
http://www.youtube.com/watch?v=rwXVSBNNre0