I am at a loss as to how or why this is happening, here is the backstory. The Rebok Treadmill 5.1 control board was fitted to my "other make" but same style board treadmill around 12 months ago. Its 240vac input, output is 0 to 200vdc & 10a cont 20a peak controlling a 1.5HP dc motor.
It has had limited use of maybe 1mile per session max a couple of times per week and has performed as expected until now.
The spade terminal marked L2 on the board pictured has 1 connection on the track to a current limiter NTC 3D-20. Its this spade terminal that gets to 60Deg C while all others are 20Deg. The case of the limiter is 25-30 deg c.
I resoldered the spade to the board thinking is had a bad joint, no difference, I replaced the 240v ac neutral cable and terminal plug onto the blade terminal in case the cable was hi resistance where it terminated on the spade. No difference. The AC current measured when the machine is running at 4mph with no load is 1.3 amps. The DC current is 2.8 amps.
The other board components measured no more than 23deg C when tested with an infra red temperature gun. The dc motor runs at 30-50 deg c.
Logic tells me its still a problem with the soldering of the blade to the board but I cant see how, is it something to do with the current limiter?

 

Is the blade oxidized or pitted? Try polishing with a fine Emory board. Also check the mating connector for the same issues.

 

I am going to solder the neutral wire direct to the pcb track where the blade connects today and check the temperature again.
Edit: I have now soldered the wire direct and the heat hot spot has moved to the leg of the current limiter where it connects to L2 track. I also found the limiter was getting hot also but for some reason my infrared heat checker wouldnt read off the black casing. Grab it with your fingers and its quite hot to touch.