Washer goes through the most of the cycle but stalls/stops at rinse cycle. Will work again if I manually advance the timer. I’m assuming that the timer needs to be replaced but want to get some feedback before buying a new part. Thanks for any advice.
Looks like you are on the right track and the cause of the problem is a faulty timer. You can order the part from AppliancePartsPros.com with no any risk because if the new part would not fix it, you can return it even if was installed.
The timer AP2045882
Here are the break down diagrams for your GE washer [MODEL]WPSR3120W0WW[/MODEL]