Just for interest as fault fixed - I had an LOS on my ONT last week 2 months after install - nothing intermittent before etc and some neighbours still on so looking at something splitter or downstream.
Using a visible red light source the OR engineer couldn't see any red light spilling at the splice in the CSP - they did wonder initially about the connectorised cable from the CBT as everything looked OK visually internally - but did then break open the splice and absolutely no visible light from the inside out cable.
So decided to replace it - no visible physical damage to the fibre at all, but no light being passed and new one works just fine.
Myself and the engineer were a bit surprised - given there was no external damage and it worked fine for 2 months! I think I heard the original engineer say a light reading of ~16 and the same on the new cable - so not sure what has gone on there. Obviously it degraded enough to give the LOS.
The old cable was away in their rubbish bag - maybe I should of asked to keep it and see if the connector was faulty or there was a mysterious break in the fibre!
