Jacuzzi Hot tub watchdog mode

Question
QUESTION: I have a 2004 jacuzzi j365 lcd. The unit is in watchdog mode. Over temp and temperature sensors ohms check good. Replaced temp sensor with new one. Didn't fix the problem. When I disconnect the sensor harness and turn power on, I get error readings of ILOC and SN3. Not having a test harness, what can I check before replacing entire circuit board?

ANSWER: You will get the iloc and sn errors. If you know of this test harness why not make one. Try removing all pumps, blower and ozonator and try when all external components are disconnected and it still comes up watchdog then try a new keypad if you have a convenience panel unplug it from the main panel ribbon cable. In my years of service on Sundance and recently Jacuzzi the watchdog was caused mainly by the temp sensor you replaced, a bad circ pump and a bad keypad. I have fixed, replaced or repaired everything on these spas at some point even boards.

- FOLLOW-UP -

QUESTION: I dont have an ozonater or convenience panel. Disconnected pumps and blower, still in watchdog. Is there any way to
tell for sure if its the lcd panel or main circuit board?
Thanks.

Answer
Only by trying a new keypad the Jaacuzzi I fixed last week the keypad solved the problem a much cheaper part than the board. You can call a tech with a keypad to try in front of you then replace but then you pay service fees we need money too or buy a keypad and do yourself. There is no tests you can otherwise do