I believe I have a DNCB 276M/162-6. The motors and everything look exactly like the ones that are in the Vending machine parts explained forum. There seems to be one thing that continues to cause the problem.
1. Pop dispenses before selection button is pushed.
micro switch fell into grove of red cam after the last selection.
Doesn't always happen. However when it does the grove the micro switches fall into is always the same one.
Problem seems to be random. It works perfectly until the MICRO SWITCHES on the SELECTION MOTOR land in the groves of the red cam thing.
Flyboy, sounds like you have vend motor brake problem also. When the motor stops on your machine 1 micro-switch is supposed to be up and one down in the cam notch see micro-switches in pic below (left red arrow). If the motor brake in pic below (down red arrow) is sticking then it will run on past and stop in the wrong position. This will happen somewhat randomly because sometimes it sticks more than others. The solution is to clean the brake with ammonia and water solution to remove sticky soda build-up. SAFETY FIRST: Be sure to unplug machine before spraying water around the motors! Clean the brake and it's hinge well and move it up and down until it moves freely without sticking. You should let the water/ammonia thoroughly dry before plugging back in machine. Vend a couple of cans to reset the cams and switches to the correct position. You should be good to go.
Let me know if you have any more problems.
Daryl