[amsat-bb] Re: Yaesu 5500 rotor problem

[i8cvs]

Hi Jeff, KB2M

Disconnect A1 and E1 from the rear of control box and measure the voltage
between input and ground at the imput of voltage regulator Q2 7806C and
it must be about 12 volt DC.

Since  the voltage you measured at the output of  Q2 7806C is lover than
5 volt DC i.e about 1 volt DC disconnect C9 , 0.01 uF and measure again.

If the voltage is still lover than 5 volt DC than the voltage regulatore Q2
7806C is gone and must replaced.

Have fun.

73" de

i8CVS Domenico

----- Original Message -----
From: "Jeff KB2M" <kb2m at comcast.net>
To: "'Amsat - BBs'" <amsat-bb at amsat.org>
Sent: Thursday, July 21, 2011 3:25 AM
Subject: [amsat-bb] Re: Yaesu 5500 rotor problem


> Thanks for all the replies on my 5500 rotor problem! I had some time
tonite
> to work on it and here's what I got. On both a1 a3, and e1 e3 pairs I'm
> reading only 1.0 volts. Between a2 a3 , and e2 e3 pairs I see only .5
volts
> at half range, IE an elevation of 90 degrees =  a reading of .5 volts. I'm
> going to order a new Q2 UA7806C and this should do it. Only question I
have
> is why Q2 failed to only output 1 volt, don't they usually fail and output
0
> volts? I'm thinking it might be something else in the circuit feeding
power
> to Q2. If so I will work this further when I actually take the rotor box
> apart with the new Q2 in hand. One other thing, I wish I can find all my
> components' I boxed up when I moved. I bet I have 10 of these in stock :)
> Thanks again for all the help guys, the electronic copy of the manual was
a
> big help as I can't find my copy....
>
> 73 Jeff kb2m
>
>
> > I'm having a problem with my 5500 after a thunderstorm. What is
happening
> > is that the rotor works manually, but doesn't display az and el
> information
> > on the control box. Also when I try to use computer control it goes all
> the
> > way to stop in both azimuth and elevation. I'm thinking this might be in
> the
> > control box, as both az and el are doing the same thing, the control box
> > being the single point of failure. Did anyone ever have this problem?
How
> > can I diagnosis what chip might be at fault without a schematic. I
vaguely
> > remember having this same problem after a close  lightning strike with
my
> > prior az el Yaesu box about 14 years ago but don't remember what chip I
> > swapped out, or how I determined which one was at fault. This getting
old
> > thing really sucks. Any help would be appreciated.
> >
> > 73 Jeff kb2m
>
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