I tried a couple of things, but no fundamental improvement of the missing LED light on the timing board.

- The power supply cable to the timing board at c1iscex indicated +12.3V

- I swapped the timing fiber to the new one (orange) in the digital cabinet. It didn't help.

- I swapped the opto-electronic I/F for the timing fiber with the Y-end one. The X-end one worked at Y-end, and Y-end one didn't work at X-end.

- I suspected the timing board itself -> I brought a "spare" timing board from the digital cabinet and tried to swap the board. This didn't help.

Some ideas:

- Bring the X-end fiber to C1SUS or C1IOO to see if the fiber is OK or not.

- We checked the opto-electronic I/F is OK

- Try to swap the IO chassis with the Y-end one.

- If this helps, swap the timing board only to see this is the problem or not.