[Icom] IC751 owners - Help please!

Fri, 27 Dec 2002 16:02:52 -0000

> -----Original Message-----
> From: [email protected] [mailto:[email protected]]On
> Behalf Of Srikanth Bhat
> Sent: Friday, December 27, 2002 3:19 PM
> To: [email protected]
> Subject: [Icom] IC751 owners - Help please!
>
>
> Hello,
>
> If you own the IC751 (not the 751A), have a digital
> multimeter and a couple of minutes to spare, please do
> read on to help me.

I do not own that radio, but perhaps I can help you.  Several years ago I
had the same problem with an IC-740.  Immediately upon switching on, it blew
the fuse.

After studying the schematic I decided to disconnect the power to all the
sub-assemblies in the radio.  I then applied power and watched the fuse.
When the fuse did not blow, I powered down, connected another sub-assembly,
and applied power.  When the fuse blew, it was the last board I connected.
In my case it was a power distribution board.  It had several caps on it.

I pulled the board.  It was shorted.  Well of course it was, there was a
meter lamp attached to it.  I removed the lamp.  The short went away.
Hmmm...  maybe not this board.  I reinstalled it, and continued on.  Finally
I had the radio working.  Most curious.  So I reinstalled the meter lamp,
put the radio back together, and turned it on.  The fuse blew!

To make a long story short (pun intended) I still have that SHORTED METER
LAMP in my parts box.  What a lesson!  That 740 later had all the
accessories removed and sold individually, then the radio was sold without
the accessories.  All was working great, and still is AFAIK.  Made a lot
more that way.  I kept the EX-243 Electronic Keyer, which I will someday
install in my IC-735.

Perhaps this technique will help solve your problem.  Good luck, and I hope
you have it up and running for the new year.

Mike.  KD9KC
El Paso, Texas.