TM 5-3895-374-24-1 Chapter 9 Troubleshooting Troubleshooting Module Problems Using the LCD TROUBLESHOOTING CONSIDERATIONS MODULE DISPLAY COMM LED PROBABLE CAUSES RECOMMENDED ACTION LED Illuminated Red ROM Memory Failed Checksum Test Reset module ERROR 100 LED Illuminated Red RAM Failed Read/Write Test Reset module ERROR 200 LED Illuminated Red Keypad Malfunction Reset Module ERROR 300 LED Illuminated Red Configuration Memory Failed Checksum Test 1.  Cycle module power ERROR 400 2 Reconfigure module Refer to chapter 3, Module Setup Procedure BACKLIGHTING OFF LED Illuminated Red Insufficient Power Supply Voltage Check Power Supply BACKLIGHTING FLASHES ON AND OFF LED Illuminated Red Insufficient or Unregulated Power Supply Voltage Check Power Supply LCD BACKGROUND IS SOLID BLACK Any Enclosure is Too Hot 1 Adjust display contrast, turn pot clockwise 2 Operate within temperature specifications LCD CHARACTERS ARE OUT OF LINE Any Enclosure is Too Hot or Module is Exposed to Sudden Temperature Change Allow temperature to stabilize LCD IS DIFFICULT TO READ Any Backlighting was Turned Off Reconfigure module Refer to chapter 3, Module Setup Procedure LCD CHARACTERS UNINTELLIGIBLE Any Water Contamination in Module Correct condition Improper Initialization Reset module Module Configured for a Foreign Language Reconfigure module Refer to chapter 3, Module Setup Procedure LCD APPEARS FADED OR NO DISPLAY AT ALL Any Enclosure too Cold Adjust display contrast, turn pot counter clockwise Module Subjected to Excessive Heat or Humidity Disconnect module, contact your local Allen-Bradley representative page 3-397