Something has to pick up the relay in order to get HV DC.
Max.

 

I thought the same thing so I plugged all the connectors back into the board that has the working bridge rectifier (except for the motor leads) and turned the treadmill on. Heard the relay click when the motor was supposed to start and then I followed the voltage back.

Issue seemed to be both that U shaped heavy duty jumper in front of the FETs as well as the blade connector that’s soldered to the board and gets connected to the positive motor wire. Resoldered the jumper and replaced both the male and female blade connectors to the positive motor lead as they appeared very oxidized from the heat, and much to my surprise it works. Thanks for all the assistance, appreciate it!

I am going to pick up another bridge rectifier and try to get the other board working as a spare. Are there any recommendations for the white thermal paste that’s used between the rectifier and the heat sink?

 

Wakefield Make small containers of heat sink compound.
You could try automotive parts stores, but don't buy silicon grease, different animal.
Max.

 

Thanks, I was looking at thermal grease as that’s what came up when I searched thermal paste, and I see that it’s silicone based. Searched heat sink compound instead and the white paste came up, 100% synthetic but non silicone type 44.