toucan58

I posted long ago and never got even a nibble. My Jandy LT400 has no lights whatsoever on the Heater control panel. I tested the test points on the secondary side of the transformer and I get good voltages, both 24V and 12V for the common/red test point and the common/WY test point. I decided that the transformer is getting power and is outputting the correct voltage. I tested between common and test point 4 on the heater controller and I get 28V which is good. I tested the fireman's switch terminal block and all tests good. However the heater control has no light for either the spa or pool side and the heater itself just sits dead. I hate to just buy a $500 heater control card without being sure but if I am going to fix this myself it is the only option I have. Could anyone throw me a bone as to how to be better sure that the heater controller card is indeed bad? Either that or tell me I am silly for trying this myself.

Hello, I have a LT-400 that has worked pretty well for about 6 years. I went to turn it on from my aqualink and noticed no lights at all on the control panel. Pressing the button does nothing. I got my volt meter and confirmed that the transformer was getting 240 VAC. There are 4 wires on the secondary side 1 red, 1 yellow , 1 yellow white and 1 green. the green is assumed ground. the red shows about 29 VAC. the yellow-white one shows 14 VAC. the yellow one shows 0. I am leaning towards the propblem being in the pretty expensive control panel board but I sure would like to be more sure about this before I buy anything. Can you guys help with this? Many Thanks