Dispenser stops shooting items when full
Solution 1:
When the dispenser is full, the comparator is getting a signal strength of 15 from the dispenser. The signal from the repeater that it leads into is giving at most a signal of power 12 to the side of the comparator:
As 15 > 12, the comparator remains on.
To fix this, you should have the repeater lead into a comparator clock, rather than using the same comparator to detect the items in the dispenser and act as a clock. E.G:
