[ICOM] IC-W2A failure

[Stephen Budensiek]

Eric,
   Just a couple thoughts.   I've seen a soldier connection break on
the power jack many times in consumer electronics.  So when you pull
the power cord out, and insert the battery, voltage is going to the
power jack, but not out of it to the radio.   I've also seen the
contacts on the power jack contacts get bent/wear out, so when you
unplug, the path for the dc power is still open (keeps you from
running the radio on the charger, and having lot of AC on your
transmit signal).   These are very common problems on equipment of
this era, ham radio or not.   Typically you have 3 or more soldier
tabs on the jack, power in, power out, and ground, some later ones
have a double ground tab for 4 soldier points.   The surface mount
tabs come loose extremely easy, doesn't take much of a push or turn
action when inserting, removing the radio, or having something fall
against it while the plug is inserted.   You can soldier the power
in/out tabs together if it's an internal contact problem, just don't
transmit while charging.   Broken soldier points can be real hard to
see, ohm things out (and you can get deceived by having contact when
you put the test lead on it, and not again when you remove it).   It's
more reliable to find a point away from the jack to test continuity,
that way you won't run yourself in circles.   Hope this helps.

73's de Stephen, K0SD in So FL

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

On Mon, May 18, 2009 at 5:10 PM,  <kk2ed at comcast.net> wrote:
>
>
> Good Afternoon,
>
>
>
> I have two Icom IC-W2As that have failed in the same way. One a while back that I shelved, and another that failed again today in the same way.
>
>
>
> After plugging in the BC-77A wall charger into the radio's DC power jack, the radio will no longer turn on.  Even once the cord is unplugged, the radio will not turn on. The battery is good and has a full charge from a rapid charger. The radio worked fine before plugging in the charger.
>
>
>
> If I take my bench variable power supply and set it to 7v, then connect clip leads to the radio's battery terminals, the radio still will not power on.    However, when the BC-77A charger is plugged into the radio, I do see a DC voltage at the terminals which I'm guessing would charge an attached battery. The connections at the DC power jack are fine.
>
>
>
> Looking at the schematic, I see that the +DC line is fed into some sort of protection/limiting/charging circuit which is located on a sub-pc assembly where the battery terminals are located. I am measuring +DC into this board, and the regulated/protected "Vcc" 12v voltage is leaving this assembly and being fed to the main logic unit.
>
>
>
> Evidently, something is preventing the CPU from starting (powering on) the radio.  I thought I heard that this was a common failure mode for this model/series HT years ago when it was popular.
>
>
> A call to Icom amateur support wasn't worth the time involved. Unless you are calling with a simple user problem, they don't offer much support. You can't even speak to someone who does component level repairs anymore!
>
>
>
> Has anyone here on the list troubleshooted a similar failure in the IC-W2A series radios before, and have any suggestions?   Or seen this failure mode before?
>
>
>
> Thanks
>
>
>
> Eric
>
> KE2D
>
> ----
> Your Moderator: Dick Flanagan K7VC: icom-owner at mailman.qth.net
> Icom Users Net: Sundays, 1700Z, 14.316 MHz
> Icom FAQ: http://www.qsl.net/icom/
> To support QSL/QTH.net: http://www.qsl.net/donate.html