Hi All,
I have a old treadmill with very strange issue. Treadmill is working fine on small speed (up to 10km/h) ,but when I increase it treadmill shakes and motor stops. ( probably it will happen the same with lower speed if I would be walking on it )
Motor is ok - as I have tried this board on different treadmill - was the same issue.
Cant find any schematics but this board is similar to MC-65 or 60 schematic attached.

I have tested all diodes + resistors (in the circuit )

What I replaced so far was :
Thyristors - Q3, Q2
DIODES - D13 D15 D16
MOSFET - Q5
MOSFET DRIVER U4
OPTOCOUPLER - U2
AMP - U3
REG - RG1
Q4 and U3

It is impossible to buy this board anywhere so I have to repair it , not many components left to replace .



Thanks in advance

Kamil

 

Just an observation, D13, D15, Q3 & Q1 centre pins are not soldered to the copper. (Top surface).
Good luck.......

 

Just an observation, D13, D15, Q3 & Q1 centre pins are not soldered to the copper. (Top surface).
Good luck.......

Thanks , yes they are