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@comcast.net To: "'Amsat - BBs'" amsat-bb@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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