ASA Dial Stuck

[gw2424]

I am playing with an Olympus OM10 and the ASA dial is stuck. I am trying to use Kodak 400 film but the dial is set at 100.

Is there some sort of unlocking button?

Thanks

 

[David444]

.

 

[gsgary]

If it is stuck just meter at 100 and alter settings 2 stops