Code 21247: “LLS – Bank 4 is off”

Note

While this warning message appears, the projector can keep on playing with a noticeable color/brightness difference. However: If no timely actions are taken, this warning will eventually increase in severity and the light source can shut down (if more laser banks start to fail).

Situation

Solution

Laser bank is off due to other laser bank related errors.

Look in the projector log files for error entries for this specific laser bank before it was turned off (other than this error).

These errors are of the format “LDM 1–x – LLS bank y [error name]”. Resolve these errors first.

Laser bank didn't switch on because of failing self-test

While the projector is in service mode, go to Communicator and go to Diagnostics >> actual >> Currents. Check the current of the laser bank.

  1. No current: Check / reseat the cabling between LDM module and light source laser bank. Check / reseat the cabling between Light source and Light source PCB.

  2. Current ≤ 630 mA: Check the light sensor functionality, the cabling and the mounting (check for errors mentioning one of these).

    Also check the optical alignment to maximize light output.

Bad / No connection between LLS and LDM board

Check / reseat the cabling between the LDM board and LLS. Check the connector on the laser subassembly PCB.

Error appears on 3 consecutive laser banks, controlled by the same LDM board: Defective laser driver

Temporary swap 2 Blue Laser driver boards in the LDM and check for the “bank x is off” messages. Ignore any other new messages triggered by this swapping.

  • If the warning changes to other laser banks, replace the LDM driver board. See service procedure "Replacing a Driver Board in an LDM Module".

  • If the warning remains on the same laser banks, replace the driver cable.

  • If problem persists after replacing the cable, replace the entire LDM. See service procedure "Replacing a Laser Drive Module".

  • If problem persists after replacing the LDM, the laser banks are defective.

Do not forget to place the swapped LDM boards back in their original position after the check has been completed.

Defective laser bank

Replace the light source. See service procedure "Laser Phosphor Light Source".