Mastertemp 400 Not Starting

[sknad]

Moved from here.
This morning I had a similar issue, but after going through the start up sequence the display went dark and now I can not get it to come back on. It did come on briefly after about an hour of messing with it but shut off again. Fireman fuse is good, heater is a pentair 400 about 5 years old.

 

[sknad]

This morning I went to fire up the heater (worked fine a few days ago), it cycled through the start up and displayed. 888 with the service heater light and spa and pool lights on. Non of the buttons worked though, flipped breaker and with the exception of one time it will not turn back on. Fireman’s switch seems fine, fuse is good but the panel appears dead. Heater is only about 5 years old. Any suggestions before I look at replacing the board?

 

[wireform]

Try This. I had one this summer.

 

[Poolbreh]

Hi, is the heater hooked up to automation?
and every time you cycle power on and off you get the revision display but none of the buttons work? Do you get any errors on the back of the board or fenwal? I am also leaning towards bad membrane.