My whirlpool washing machine model LA9500T suddenly today stopped advancing from cycle to cycle. It fills water correctly and goes into agitator cycle. It then keeps agitating until I manually advance to next cycle, on and on. What can I do to fix this and is it repairable by me (I can do small stuff). Is it going to be expensive in parts? This is an old washer, about 16-17 years old.

Thanks for help.