2018 Daito Bancho A CO error

[C-M-K]

Appears when attempting to put coins in. I am able to reset it by pushing the blue button on the inside, but it shows up again whenever another coin goes in. And of course it doesn't take coins while the error is up. Can't see anything physically wrong with the coin mech. Please help.

[Drunkenclam]

Suspect faulty/dirty sensor in the coin mech.

[C-M-K]

But where is the sensor at? All I see is a lever that the coins hit on the way down!