Washer does not switch from

Washer does not switch from wash cycle to rinse cycle, the time gets stuck on 33 minutes. You can hear the motor humming. I shut the cycle off. and turn the machine on rinse/spin cycle. Then the time gets stuck on eight minutes. The washer does empty itself of water and spin, but the cycle gets stuck, i open the lid about a dozen times until it gets past the 8 minute mark. until if finally finishes the cycle. Help