Help! Jacuzzi J 345 /W keeps rebooting

[David B]

Hello all,
I have a used '04 Jacuzzi J 345 /W with a OT chip (I was told this chip allows the tub to go to 106 degrees).   My wife said the tub displayed a high temp (she doesn't remember the number, 100+) but the tub was actually very cool (85 degrees?).  She cycled power at the circuit breaker and watched the tub reboot and the temp climbed from 70 degrees to 84, to 93, 104, to, I think, over temp.  Unfortunately I didn't do the best job gathering info in the beginning, I thought it was a simple bad temp sensor.
I drained and cleaned the tub and replaced the temp sensor.  I refilled the tub and reapplied power.  Now, when the hot tub boots up I see a number, 355.  (I think this is just software version), pump 1 kicks on as usual then after several seconds the tub shuts off and reboots and the cycle starts over again.
I can run pump one at high/low speed.  I can run pump two.  I can run the circ pump.  I've ohmed out the heater.  I've disconnected all pumps, heater, stereo, lights and reconnected one at a time and tested.  I've reseated the eprom chip.  Nothing seems to help.  My only guess is the eprom which I can't really test or the transformer.  If the transformer is not supplying enough power to the controller will the controller display an under voltage fault or just reboot?  I verified that I'm sending 240 VAC to the transformer but I only see about 2 VDC coming out. 
Has anyone seen this before or have any ideas?

Thanks, David

[clover]

Initial diagnosis was correct, bad temp sensor. 

New symptom could be self inflicted.

New symptom could be in the sensor loom, check to be sure all sensor pins are secure in the loom and not being "pushed back" when going back on the circuit board.

New symptom would not have anything to do with the e-prom unless symptom occured after you "reseated" the e-prom chip.  it would only take 1 of those catepillar legs to not go in correctly, or fold underneath the e-prom and not go in the receiver that could cause a problem.  Before removing it again, inspect the e-prom pins on both side to see if they did not go in correctly.  Use a light and mirror to see above and below.

[Jacuzzi Jim]

 Also look at the capacitor, center of board blue I think, is the end of it bulged out?

[Tman122]

I would look at the high limit sensor also. Back side of heater tube