Maintenance & troubleshooting, Mighty mule 500 diagnostic led’s, Maintenance tips – GTO UL325 SERIES User Manual
Page 36

Maintenance & Troubleshooting
33
• On all gates weighing 250 lb. or more, routinely
grease the ball bearing hinges at least 4 times a year; 
more frequently if the gates are near a coastal area.
 
•		Keeping	a	few	mothballs	in	the	control	box	will	
discourage insects from entering it and damaging the 
control board. 
• Clean the push-pull tube with a soft, dry cloth and
apply silicone spray to it at least once per month.
• While oxidation is a normal part of weathering
of equipment that is exposed to the elements, we 
recommend you apply silicone spray to the front and 
rear mounts to minimize this effect.
Maintenance Tips
Diagnostic LED Symptom
Diagnosis
Check
Status (clear)
Blinks Once
Received input from 
transmitter, keypad, or other 
accessory.
Use to see if the circuit board is 
receiving input from transmitter, keypad, 
or other accessory.
RF (yellow)
Flickers when the remote is 
pressed.
Flickers when the remote is 
not pressed.
Receiving signal from remote 
or wireless keypad.
Receiving RF interference
Use to see if the circuit board is 
receiving input from remote or keypad.
Check for AC power near antenna or 
control box, cell phone towers, radio 
stations, etc.
AC Power (green)
ON
OFF
Receiving AC voltage from 
transformer
Not receiving AC voltage from 
the transformer
If the battery is low, check the charging 
circuit on the circuit board. If the board 
is giving a short beep, check the battery 
under load.
Check for power at the outlet and the 
transformer output.
Charge (red)
ON & gate opener functions 
properly
ON & gate opener does not 
function.		Hear	click	&/or	
warning buzzer when remote 
or push button is pressed.
OFF & gate opener functions 
properly.
OFF & gate opener does not 
function.
Battery has been fully charged 
to 14.5 vdc.
Battery is low or has been 
disconnected and transformer 
or solar panel is powering up 
the circuit board.
Current has been drawn from 
the battery and the circuit 
board is charging the battery.
Transformer or solar panel 
may is not charging, battery 
is very low, or battery is not 
taking a charge. 
The battery should have 12.5 to 13.5 vdc.
Check the battery and connections
The circuit board should charge the battery 
to 14.5 vdc. The charging circuit 
Transformer or solar panel, battery, and 
charging circuit on the circuit board.
Mighty Mule 500 Diagnostic LED’s
