[Premium-Rx] HF-2050 "fault" help

[Rodney Bunt]

DAve,

I think you have the easiest fault to fix on a HF-2050. My opinion is that you have a faulty power
supply. Typically the BIG electrolytic capacitors in the PS go faulty. NOTE: that PS runs HOT!, so
there could be other problems in the PS, so check all the output voltages. The "Fault " indicator
has some comparators looking at all the PS voltages, and if they are high or low you get the
"fault" light coming on. Nearly had heart failure one night when the fault light came on, traced
it to the mains voltage took a sag late at night and the PS had low voltage on one of the outputs,
so put it on the variac, and wound up the input voltage, all was fine again. Not a lot of slack in
the "off the shelf" unit that collins used in this rig. Do yourself a favour and install one of
those PC fans INSIDE the PS area, I use a 12V one connected to the 5V output, just ticks over and
is VERY quiet, but moves the air and reduces the temp of the PS, fine.

PS: I have seen entire front panels including LCD display and all controls NEW on eBay. I bought
one myself, as my front panel had a few battle scars, it's still in the wrapper!

Regards,

Rodney
VK2KTZ
Sydney

--- Dave McAllister <davemcallister at hotmail.com> wrote:

> Hello all, 
>  
> New to the list and first post.  I was hoping my first post would be an intro, but 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
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