Re-Everything works except heater: Pageup, again I want to thank you for your help.

I reverse engineered the "Temp probe" circuit, made a schematic leaving the "2721" a box with 8 pins, sent it to an engineering friend who modeled the circuit. He determined that the IC was not a 2721 but a 272 I and sent the infor back to me. Knowing what the IC pin out was, I determined the part to be defective and replaced it, reinstalled the circuit card and the spa worked like it should. I also found out that the original temp probe was defective. Replacing the temp probe cos $45 and I had a Op Amp (IC) similar to the 272 I. Bottom line, I was able to repair the Baja Sport Tub for $45.00 but no thanks to Hydro-Quip or Gecko Electroniques in Canada. Neither company would even tell me what the IC was or offer any help. They won't get my vote or my money if ever I was to buy a spa. The retired couple (spa owners) won't be buying anymore of their products!! The company Baja Spas in Arizona were helpful on the error codes but knew nothing about the electronics. I'am going to try and dig out the temp probe and determine whats inside the metal probe. Then if it goes bad again we'll be ready! As I did not charge the owners for labor/repairs, their only out of pocket expense was $45 for a replacment temp probe.

Again, I want to thank you for your help and support. If I can be of help please let me know.

Logi98,
Tom

You won't find any company that will willingly give out any information at the component level of a circuit board. In fact most of the people that work for the companies don't have any accessability to that information. They have a technical team to design the spas, and often contract out the electronics work to other companies (in your case Hydro Quip contracted Gecko to do that). You will run into that problem with any spa manufacturer.