blang

Now, without the top side keypad connected I am getting a click like it's trying to fire the pump on every reboot. But still getting constant boot loop.

Thanks for the reply! I am in Barrie, ON. I'm assuming it's a board level repair? I wish I were confident in my soldering skills 🙃

Sorry to bring this topic back from the dead, but I have 100% the exact same problem. And funny enough, the exact same model of Serenity 5000G. @buriboi did you end up replacing the spa pack? I was really hoping it would be something less expensive 😆 I am going to remove the spa pack and have a look since I have exhausted most of the other recommendations in this thread. I was curious if the spa would fire up without the topside control panel connected, and thanks to this thread, I now know! Cheers!

I have had my tub empty for the summer, just filled it and went to power up last night. The top side control panel lights up, and goes through its boot up process and just as it is going to start the pump it reboots and starts the light up process again. I have powered down, unplugged the Pump, control panel, and light connectors from the spa pack and reconnected. At one time i would get a click from the pump just before it would reboot. Then after power down a couple more times the pump actually started up for about 1 second and then continued the reboot loop. I have left the tub powered off over night and today when I power it up I am back to just the reboot loop, not even a click from the pump. I have replaced the 25amp fuse (not replaced the 20amp yet), also tried powering up without the pump connected to the spa pack. Still getting just the reboot loop. Any assistance is greatly appreciated before I bring in a service tech. Is there anything I can test on the board itself or look for? Thanks!