10/31/24
Message Overview:
Message Name:
LAVATORY OR GALLEY WATER SYSTEM 'ACTIVE' LED IS NOT ILLUMINATED
| Identifier: | 381OBS003 |
| Effectivity: | Aircraft 20501 - 20999 |
| System: | Waste and Water |
| Associated CAS: | None |
| Reporting LRU: | Water Module |
| System Description: | SMM 38-10-00 |
| Schematic Diagram: | None |
| Wiring Diagram: | SWM 38-10-00 |
Message Description:
The lavatory or galley water system 'ACTIVE' LED is not illuminated.
Possible Causes:
- Water System Circuit Breakers OFF
- GLY WTR SYST Circuit Breaker
- LAV WTR SYST Circuit Breaker
- Water Pallet
- Associated Wiring
Required Conditions:
- Aircraft power ON
- Cabin Management System ON
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: None
NOTES:
- Refer to the following document Water System Guide & Troubleshooting
Quick Links:
| Functional Test of the Potable Water System | SMM TASK 38-10-00-720-801 |
| Removal of the Water Tanks | SMM TASK 38-10-01-000-801 |
| Installation of the Water Tanks | SMM TASK 38-10-01-400-801 |
| Removal of the Water System Pallets | SMM TASK 38-10-03-000-801 |
| Installation of the Water System Pallets | SMM TASK 38-10-03-400-801 |
| Standard Practices - Wire Repair | SPM 20-12-10-02 |
Troubleshooting Recommendations:
- If there is no power to the water module the 'ACTIVE' green LED will not illuminate.
- Locate the Circuit Breaker panel at the Galley or Lavatory depending on which 'ACTIVE' LED is not illuminated. Make sure that the GLY WTR SYST or LAV WTR SYST breakers are pushed in.
- If YES, the breakers are in then continue with the next step.
- If NO, then push in the Galley or Lavatory breaker and make sure the green 'ACTIVE' LED illuminates and do close out.
- Gain access to the water module on the water pallet. Press the reset soft button on the water module. Does the 'ACTIVE' LED illuminate?
- If YES, then do the functional test of the potable water system. If system is okay, then do close out.
- If NO, then continue with the next step.
- Pull the GLY WTR SYST or LAV WTR SYST breakers depending on which water pallet has the issue.
- Remove Galley connector A84106P1 at the Galley Water Module. Push in Galley breaker GLY WTR SYST. Perform a voltage/continuity check per the table below:
FROM (GALLEY) TO EXPECTED RESULT RESULT A84106P1 - 23 A84106P1 - 19 28 VDC A84106P1 - 27 Airframe Ground Continuity A84106P1 - 19 Airframe Ground Continuity - If YES, there is 28 VDC at pin 23, then replace the Galley Water Pallet.
- If NO, there is not 28 VDC at pin 23, then check pins 27 and 19 grounds. If grounds are okay, then repair or replace wiring from the GLY WTR SYST circuit breaker to the water pallet.
- If the grounds are not okay, then suspect GS7122 or chassis TB84004.
- If the wiring check is okay, then go to step 7.
- Remove Lavatory connector A84105P1 at the Lavatory Water Module. Push in lavatory breaker LAV WTR SYST. Perform a voltage/continuity check per the table below:
FROM (LAVATORY) TO EXPECTED RESULT RESULT A84105P1 - 23 A84105P1 - 19 28 VDC A84105P1 - 27 Airframe Ground Continuity A84105P1 - 19 Airframe Ground Continuity - If YES, there is 28 VDC at pin 23, then replace the Lavatory water pallet.
- If NO, there is not 28 VDC at pin 23, then check pins 27 and 19 grounds. If grounds are okay, then repair or replace wiring from the LAV WTR SYST circuit breaker to the water pallet.
- If the grounds are not okay, then suspect GS7231 or chassis TB84005.
- If the wiring check is okay, then continue with the next step.
- Replace the affected water pallet.
- Do close out.
