I have a model 3110 SportsArt treadmill. This model has a circuit board in it with model number 3108 V2.5 DRV. The thermistors on this circuit board need to be replaced. The thermistors have a part number on them that says UTI 20SP 2R5. I called SportsArt and they said the unit can also use part number 25SP 1R5 thermistors, but they do not sell individual parts only complete new circuit boards. How much would it cost to perform this work and test the circuit board for normal function afterwards?