Hello We have two Yeasu 5400 AZ EL rotators with the associated controllers and the same problem. Both are about 15 years old and generally work. There is a procedure to set it up that calls for the operator to drive the AZ and EL to the 360 and 180 to set the full scale deflections. We can do this and see the required 4.5VDC on the two appropriated pins in the back. When we drive the AZ and EL back to zero, it is typically short about 10 degrees. We have attempted this adjustment several times to find the happy medium between the few adjustments but we can never get the full span. Does anyone know if there is something inside the control box we can change(or modify our set-up procedure) to get a fuller span on the AZ EL meters? In looking at the schematic, and also on the inside, we didn’t find another hidden pot to do this. If anyone can help, they also email me directly if they wish at [email protected] and also [email protected]. Tnx and 73dB de WS8P G'day