caldera temp display 115 tub cold

[2tubagain]

The tub is a caldera tahitian paradise.2004
Tub not used in a week went to do the weekly shock and the display temp read 115 touched the water it was cold!
Thinking of the fast fix went to local retailer and purchased thermister and high limit not even taking the time to get the meter out and ohm out the thermisters.
Install both, no help display reads the same 115.
LIM, led on pcb board is green, all other functions working, control pcb cycles the tub.
I would like to get the test points for this control pcb and maybe the tech service manual, or any help would be greatly Appreciated.
I love this tub, put days in research before purchased but before I shell out the coin to replace the control pcb for just temp control issue only would like to diagnose some more.
Thanks much for your time

[2tubagain]

Diagnostic PERFORMED:
1)Water temp is 65degress
2)Check circ pump; running, builds good pressure to firmly force pin to micro switch.(pressure switch)
3)replaced temp control thermister and high limit thermister/ohmed out old thermisters both function fine.
4)checked control board AC/DC power supply for control PCB, voltages marked all ok.
5)Pulled heater relay PCB; no relays froze in open position/no signs of over heating9burn).
6)while power on; pulled ribbon cable from control display to control PCB led indicator on main PCB
turn red; next to led print says "display disconnected"(indicates to me PCB safety measure is working)
7)jumper settings on control PCB to set PCB for model of tub; J9 is for this tub;J12is for same tub but metric; PCB shifts with no problems.
8)reset of control PCB(power off/on) control PCB runs self check with set temp (102) then Led on PCB with print LIM ON lights green; display then shows 115 degrees with solid TEMP next to it, then TEMP will flash/LIM led still green.
9)when power is cycled from off/on after couple of minutes tub cycles blower/pumps like it should. and clean cycle is 10 minutes.
It appears most of the control PCB is functioning as it should but the dam thing is locked in to some kind of partial fault, now there may have been some kind of high lim situation, we did have some nasty thunder storms the week prior that did not kill power completely but quick drops that may have done something, but I want to believe there is a reset of some sort.
my theory is it high limed, and is stuck from resetting completley,given the LIM led is green but the fault (TEMP) is flashing and 115 degrees is displayed OR temp control/display circuit is locked on 115D??

[Tman122]

Diagnostic PERFORMED:
1)Water temp is 65degress
2)Check circ pump; running, builds good pressure to firmly force pin to micro switch.(pressure switch)
3)replaced temp control thermister and high limit thermister/ohmed out old thermisters both function fine.
4)checked control board AC/DC power supply for control PCB, voltages marked all ok.
5)Pulled heater relay PCB; no relays froze in open position/no signs of over heating9burn).
6)while power on; pulled ribbon cable from control display to control PCB led indicator on main PCB
turn red; next to led print says "display disconnected"(indicates to me PCB safety measure is working)
7)jumper settings on control PCB to set PCB for model of tub; J9 is for this tub;J12is for same tub but metric; PCB shifts with no problems.
8)reset of control PCB(power off/on) control PCB runs self check with set temp (102) then Led on PCB with print LIM ON lights green; display then shows 115 degrees with solid TEMP next to it, then TEMP will flash/LIM led still green.
9)when power is cycled from off/on after couple of minutes tub cycles blower/pumps like it should. and clean cycle is 10 minutes.
It appears most of the control PCB is functioning as it should but the dam thing is locked in to some kind of partial fault, now there may have been some kind of high lim situation, we did have some nasty thunder storms the week prior that did not kill power completely but quick drops that may have done something, but I want to believe there is a reset of some sort.
my theory is it high limed, and is stuck from resetting completley,given the LIM led is green but the fault (TEMP) is flashing and 115 degrees is displayed OR temp control/display circuit is locked on 115D??

Replace your water temp sensor, The one in the tub vessel. Seems that's all thats left to check?

[2tubagain]

did that!

3)replaced temp control thermister and high limit thermister/ohmed out old thermisters both function fine.

[Tman122]

did that!

3)replaced temp control thermister and high limit thermister/ohmed out old thermisters both function fine.

Gota be in the board.

[2tubagain]

For those who find themselves in the same situation follow the process of elimination that I did, but do not run out and buy temperature probe(thermister) or high limit (thermister) before checking their ohm resistance first.
 All in all if the thermisters are fine and the control pad clearly functions everything else other than display correct temp then as I did rule the display out, added with the heater LED on the advent control board not lit up!!!
That leaves the advent control board, nw there is nobody offering the control PCB board alone; you must buy the whole control box!!!!!
Now I found the cheapest price from the good folks at hottubspasupplies.com. They beat everyone local and on the net by a hundred plus dollars and free shipped it to boot, delivered in four days. The control box even had the upgraded heater relay board.
Removal/installation took 45minutes and the tub is running fine heater is working hard to warm up from 64 degrees.
In ending;  I posted my dilemma on four deferent forums and received one each reply from forums  one and two,  nothing on the third and erotica and local hotties that want me from the fourth(spaforums.com)!!!!
whatsthebest-hottub.com and poolspaforum.com where the two where I received some help, but not from any field service person in these forums that I am aware of.
Thanks to those who posted a reply!
For those who run into this problem I hope this post helps just read through it, good luck!