My treadmill controls / heart rate monitor points is leaking current and giving a mild shock, and after "investigating" the board for more than a week the manufacturer said the treadmill PCB needs to be replaced costing ~ $200

I thought of debugging it once and I noticed that the socket where the controls is hooked up is giving enough current to be detected by a tester.
DC voltage in the leads for the motor M+ & M- shows only ~ 20V (I thought it should be 110V).

I've attached the photo of the PCB.

Any help is appreciated.

 

Where are the heart rate monitor terminal points, can you read the voltage across them ..

 

Two parts look burnt. Replacements might burn again, maybe by a bad IC or bad transformer.

 

Also PCB corrosion tracks...

 

I'll replace the board. Thank you for your kind response.