water dispenser quit

My refrigerator developed a leak at the main valve and I replaced it along with a new water filter and ran about half a gallon of water through it to clear the charcoal. Next day the water dispenser was not working. Replaced the valve again and same result. Replaced the dispenser control board and still no water. The water is getting to the valve but is not opening. I replaced the valve behind it that controls ice maker and stuff but still no luck. Any ideas?