[Yaesu] Fixing the howling audio problem on VX5R

[Robert Meier]

John W5TD,

> I have a Yaesu VX5R I recently picked up with the
> howling audio problem.
> I have read the modifications for how to fix it, and am willing to try,
> but how hard is the modification?

The VX5R is a dense body of surface mount components.  As such it can
tolerate high G stress and jerk, but is vulnerable to scratching, chipping,
solder bridges, ...

> What will happen when I open up the case?

If this is your first attempt at repairing micro-electronics,
I suggest that you
  o consider your VX5R a piece of electronics training equipment,
    not likely to survive the attempted repair,
  o consider learning SMC and microelectonics repair on more forgiving
    equipment first, or
  o ask/pay an experienced and equipped expert to help you.

If you are already comfortable reading the Technical Supplement,
soldering under a microscope, and matching 100u traces to
60cm x 60cm schematics, then you should feel confident to repair
your VX5R.

> Do I need to be extra careful so [no] pieces fall out, etc?

You need care similar to repairing eyeglasses.

There should be no loose pieces when you start (and there should
be no loose pieces when you finish).

I found it took me some gentle trial and error to understand the
"exploded view" and disassemble, but the unit was well-built,
and easy to reassemble.



You should be able to find the  "Manual", "Technical Supplement",
and "Schematic" online.  If you have trouble, I can send you
(pdf) copies upon further request.

Enjoy,
-- 
Dr. Robert J. Meier
AA9AU