Well I decided not to wait and popped one open lol.
For future reference one screw top right corner and two inside battery compartment and a gental nudge the back pops loose. Once the back is off get a fingernail under the edge of the front and that pops loose from the plastic pins that hold it together..
Once the front is loose you will see the crystals, there is only one set and they are in slot A.
This one i see no corrosion top or bottom of battery holder and batt test light on front lights loud n proud but NO sound🤔🤷🏽
As i meantioned in have some crystals from a silent keys stuff, how do I know what channel they are for and will any crystal work? Or do they need to be same type that's in it? I enjoy fiddlin with stuff like this. Esp if i can make it work! Lol
