We have a tub with a Spa Builders LX-15 pack.... every now and then the display starts scanning really slow... displaying one temperature digit every second or so. If there is a panel light on (like the pump for instance) it will also scan slowly along with the display. Toggling the power fixes it for several weeks, and it seems to be functioning fine from a control perspective... just a wacky display.

Someone in these forums last year had the same problem but there was no reply. It's either the display board or the main board... I would rather only buy one !!

Anyone else had this problem and figure out which part to replace ? I'm an electrical engineer so I know that it's the display scanning clock that is going... but would need a schematic to figure out which board it's on... anyone ever found an LX-15 schematic ??

I would initially assume that the oscillator that controls it is in the topside control panel itself rather than taking an hf clock thru the cable. (If it were, then I would imagine the entire controller would go into mega-slow mode also).

You might want to try a freeze spray or other method of cooling down the topside control panel/circuit board to see if you've got a temp dependent component on board that's going out.