Jeff -

Yaesu G-5500 Owner / Operator's Manual -- Schematic Diagram on LAST Page.

http://gatorradio.org/Manuals/Yaesu_G-5500_Operating_Rotor_Manual.pdf

If you have the paper manual, you have the schematic.  LINK to Electronic version provided above.

Fairly straight forward, component level troubleshooting with a VOM/DVM (Logic probe useful).

greg

w9gb

==

Date: Tue, 19 Jul 2011 16:54:10 -0400 From: "Jeff KB2M" Subject: [amsat-bb]  Yaesu 5500 rotor problem To: amsat-bb

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.

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