6-3 
Symptoms  Possible Cause  Corrective Action 
Touchscreen does not 
respond. 
Touchscreen disabled 
Check if there is a 
  symbol displayed above the [Main 
Menu] quickkey. If yes, press and hold the [Main Menu] 
quickkey for more than 3 seconds to enable the 
touchscreen. 
Cable defective  1. Check that the cable between the touchscreen and 
touchscreen control board is correctly connected. 
2. Check that the cable between the touchscreen control 
board and main board is correctly connected. 
Touchscreen control board defective  Replace the touchscreen control board 
Touchscreen defective  Replace the touchscreen. 
The main board failed.  Replace the main board. 
Touch position invalid  Touchscreen not calibrated  Calibrate the touchscreen. 
 
 
6.6.3 Alarm Lamp Failures 
Symptoms  Possible Cause  Corrective Action 
The alarm lamp is not 
light or extinguished, 
or the alarm lamp 
illuminates 
abnormally. 
Cable defective  1. Check that the cable between the alarm lamp board and main 
board is correctly connected. 
2. Check that the cables and connectors are not damaged. 
Alarm lamp board defective  Replace the alarm lamp board 
The main board failed.  Replace the main board. 
 
 
6.6.4 Button and Knob Failures 
Symptoms  Possible Cause  Corrective Action 
Buttons do not work  Cable defective  Check that the cable between the keypad board and main board is 
correctly connected. 
Keypad board failure  Replace the keypad board. 
Knob does not work  Cable defective  1. Check that the cable between the knob and keypad board is 
correctly connected. 
2. Check that the cable between the keypad board and main 
board is correctly connected. 
Knob failure  Replace the knob encoder. 
Keypad board failure  Replace the keypad board.