Hot tub controller trouble

[laban93]

Hi all!
I have some issues with my hot tub controller. It works for 4-5 days, then freezes and the tub goes cold. Its irregular when it happens. I must turn it off for 5 minutes then back on to get it working. I also noticed that the LCD backlight was dim, and sometimes not working. I did try to fix it by re-capping both the controller pcb and the main pcb, but nothing changed.. any ideas of where to start looking? Or anyone with any experience fixing theese?

[Runco990]

As someone who has fixed his own hot tub last year, have you looked at the control PANEL?   I thought I had a bad main controller ($2000!!!) but it was the control panel that had corrosion in it.  Seems they are not as sealed as you'd think.

[laban93]

Yeah. I opened it and resoldered the connections and recapped. Did not see anything obvious though. It previousley had water intrusion trough the cracked membrane. Fixed that by silliconing a thin sheet of plastic as a second membrane. But yeah, there is no OBVIOUS faults.. When it freeze the buttons still work to control the jets etc, but the screen and heating turns off.

[fzabkar]

It seems that the backlight might be a clue. Can you trace the circuit in this area?