I've had this Proform 540s for several years and it has never given me a problem. Recently I have had console problems which are intermittent. I have checked the wiring (unplugging and replugging the connectors several times) on both the motor controller circuit board (bottom) and at the console circuit boards (upper boards). The red LED light is always on continuously (no blinking). Sometimes everything works perfectly with all controls working as they should. Other times the display will light up, the incline will work but nothing else works. It will not decline, the built-in 2-speed fan will not work, the belt doesn't turn, etc. If I unplug the unit from the wall and come back hours later, everything will work. Most of the time, if I leave it plugged in, it will not work. Just tonight, I removed the console and plugged and replugged the wiring harness that runs through the frame side from the bottom to the console. The whole thing had been unplugged since yesterday (when I spent a couple of hours troubleshooting other things). When I tried it, It came on, everything worked. I thought it was fixed as I walked on it several minutes at different speeds, ran the incline up and down several times, fan worked. I repeated this six or eight times. I bolted the console back to the frame and tried it. AGAIN, it didn't work except the incline (it won't decline), the fan doesn't work, the belt won't start. I unbolted the console again and rechecked the wiring harness and still, I get nothing. I was thinking maybe it is getting a thermal overload but sometimes I can just get it turned on, reset the incline to flat and turn it off. Then try to turn it back on and it will do nothing again. I'm guessing it's something simple since sometimes it will work perfectly for an hour or more, then when I try to turn it back on after a walk, it does nothing but may come back on the next day, provided it's been unplugged.
Like I said, this Proform is several years old and I don't care anything about sinking a bunch of money into it in hopes it works for a few more years. I do appreciate any help.