TM 5-3895-374-24-1 Troubleshooting Your Input Modules If your Input And Your Input And Probable Cause Recommended Action Circuit LED is Device is Your input device will not turn Device Is shorted or Verify device operation  Replace device Off damaged. On/Closed/Activated Input circuit Is Verify proper wiring  Try other input Your program operates as damaged. circuit Replace module though a Is off Input is forced off in Check the FORCED I/0 or FORCE LED program. on processor and remove forces On Input device Off-state Check device and input circuit leakage current specifications Use load resistor to exceeds input circuit bleed-off current Your program operates as specification Off/Open/Deactivated though it is on and/or the input circuit will not turn on Input device is shorted Verify device operation Replace device or damaged Input circuit is Verify proper wiring  Try other Input damaged circuit Replace module Input circuit is Check specification and sink/source Incompatible compatibility (If DC input) Low voltage across the Check the voltage across input circuit Input. and check source voltage Your program operates as Incorrect wiring or an Check wiring and common On/Closed/Activated though it Is off and/or the Input open circuit connections circuit will not turn on Input signal turn on time too last for input Check timing specifications circuit Off Input circuit Is Verify proper wiring  Try other input damaged circuit Replace module Your Input device will not turn Input device is shorted on or damaged Check processor FORCED I/0 or Off/Open/Deactivated Input is forced on In FORCE LED and remove forces  Verify Your program operates as program proper wiring  Try other input circuit though it is on Replace module Input circuit Is Verify proper wiring  Try other input damaged circuit  Replace module Chapter 9 Troubleshooting (page 3-460)