I bought me one of them thar symax's Most likley a Symax I.

Had it for 19 months before this happened.

The chin bar can be detached from the helmet. Then the removal of four (4) tiny screws (see white square boxes below) that secure the chin guard inner cover will allow you to remove the foam and get at the guts. See photo above. I didn't take any after shots but given the nature of the release cable, I went to the local bait shop and had them make me a new one. Free too.
When the flip face release mechanism doesn't work the world is a bit darker and dreary...
The shiny spots/lumps are Maguire's finishing mist.


I was amazed to find so much filth upon removal of the chin bar from the helmet. Once I figured out how to get at the cable, I used Plexus to clean everything up.
Fishing tackle and motorsickle helmets. A match made in China.


P.S.: Nice to see that beefy plastic tab that holds the chin bar in place, eh? (noted with the red circles)