[Collins] HF-2050 Help

[Dr. Gerald N. Johnson]

On Thu, 2006-11-30 at 12:33 -0500, BSugarberg wrote:
> Hello,
> 
> Please reply to Dave at <davemcallister at hotmail.com> not to me
> ----------------------
> Dave McAllister wrote:
> > Hello all,
> >  
> > I'm faced with a rather disappointing problem, and I figure 
> > this is the best place to go for help...
> >  
> > I just purchased two Rockwell Collins HF-2050 receivers on an online 
> > auction (not the e-place).  Only one has arrived so far, and it is DOA.  
> > It was damaged slightly during shipping - the RF gain/noise blanker 
> > knobs are bent, and the noise blanker pot shaft has broken off 
> > completely.  I don't think this is too serious an issue, as it shouldn't 
> > take me very long to fix, assuming I can get the part.  However, the 
> > radio is almost dead.  When powered on, the fault light comes on, a buzz 
> > comes from the speaker, but nothing else.  None of the displays show any 
> > life.  I've tried pressing various key combinations, and nothing seems 
> > to do anything at all (except the volume control does affect the buzzing 
> > sound, of course).
> >  
> > Has anyone ever run into anything like this?  Does anyone have any 
> > suggestions as to where to start, or have access to a copy of the 
> > manual/service manual?  I would of course be more than happy to pay for 
> > reproduction/shipping costs if someone would be willing to send it along.
> >  
> > I have a hunch this is a power supply problem, and I'm guessing with the 
> > +5v line, but I'd rather not go poking around in there without a 
> > schematic or at least some basic troubleshooting ideas.
> >  
> > Any help anyone can give would be most appreciated!
> >  
> > 73s
> >  
> > Dave
> > VE7HUN
> > Squamish, BC, Canada

I'd start by reseating all the cards and connectors inside.

The bent RF gain knob could have broken the pot inside to make it kill
the receiver gain, but it shouldn't kill the display.
-- 
73, Jerry, K0CQ, Technical Advisor to the CRA
All content copyright Dr. Gerald N. Johnson, electrical engineer