v-fit los angeles 2 stopped working despite new parts !!?

I have a V fit Los Angeles 2 treadmill which i bought 2nd hand. All was fine for a couple of weeks then it just stopped. I called customer service who said it was most likely the PCB. I sent it off where they tested it and sold me a new PCB. I installed it and it fired up then went E1. I called them again, this time they said it was most likely the motor which was the root cause and this must have blew the circuit board. I bought the motor and installed it. Same problem, so i called again and they said the old motor may have blown the new PCB, so they sent me a replacement PCB again. Both new parts installed. I fired it up, appeared to work fine for two mins, so i eased myself on it. After 1 min at 8mph it felt like it surged then cut out, displaying E1 again !!! Im at a loss.. Please help. PS the price i have spend on new parts now exceeds the price i paid for it.. ;-(