I had the same problem with mine. It kept shutting off and we would have to unplug and plug it back in just to get it to run for not even a full cycle every day. I thought it would be a nightmare because I'm in Canada but I called Intex and within a week I received my new salt water chlorinator that works great!

Hello,
There is no code 77 Call intex and give them your information. They will have a new unit shipped to you in days
They are really good with warranties as long as you have a valid receipt