Have done minor repairs on toilet myself in past, valve, flapper etc, however I can't seem to stop a running water sound that just started. I checked the float, it was working, shutting off the water when it reached the water mark. The water shut off, the flapper was seated properly and the water was not going over the overfill valve. Still it sound like water is running in the float valve and won' t stop. I so not see any water going into the tank nor is the tank filling up. Any ideas

