[K4RY] G5400B Rotor Controller Not Working

[Kris Kirby]

On Wed, 27 Apr 2016, Sharan Asundi wrote:
> AU Radio Club,
> 
> This is Sharan Asundi from Tuskegee University. As you might be aware, 
> we?ve recently set up our UHF/VHF station. Our antennas are mounted on 
> top of the Yaesu G5400 AZ-EL rotor combination. The rotors seemed to 
> be working fine until recently but now the rotor controller is unable 
> to actuate either of the rotors. The issue started with the controller 
> have glitches actuating the AZ rotor but now neither of them can be 
> actuated. Any suggestion on troubleshooting the controller or further 
> insight will be of great help.

Page 11 of the following PDF gives the schematic for the G-5500:

https://www.yaesu.com/downloadFile.cfm?FileID=8814&FileCatID=155&FileName=G-5500_IM_ENG_E12901004.pdf&FileContentType=application%2Fpdf

Main (motor) power for the G-5500 is 28V at 2A; the exception seems to 
be that if a motor limit switch is triggered, it will need a manual 
assistance to reactivate. Check the rotor installation and make sure 
that it's not all the way at a limit. The G-5500 has a 450-degree sweep, 
which is a little over 360 degrees. If there were high winds, it's 
possible the power supply can't provide enough power over a long run of 
control cable. OTOH, the G-5500 doesn't appear to have a brake, so it's 
possible it has been blown around by winds as well.

I'd disconnect the motors from the rotor control box, attach a 12-ohm 
50W resistor and see if the power supply in the rotor control is still 
working. Once you determine where the power comes out of the rotor 
control at, you can check the resistance of the rotor cables and rotor 
motor at once and if you don't get continuity, you know a limit switch 
has opened or the rotor has twisted in the wind. 

You mention the G-5400 -- are you sure it's not a G-5500? The G-5500 has 
been around since the 1990s, and the G-5400 came along before that. 

G-5400 schematic is on a page near the back of this manual:

http://foxdelta.com/products/satellite/G5400_G5600.pdf

73,

--
Kris Kirby, KE4AHR
Disinformation Architect, Systems Mangler, & Network Mismanager
President UABARC WB4TJX