Trying to pick up a screw with a magnet pen I buzzed something on the control board. Motor works, I connected a 12V battery to it and runs. Console shows treadmill is running, counts calories, miles, time, etc. Belt won't start though. I removed the control board and checked for melted, burned, blown, leaky pieces, nothing. The board is sending 4V to the motor, when it is supposed to be sending 12V. Help. I'm not an electronics expert, but can desolder and resolder a broken or damaged piece. Just don't know how to find which one it is.

 

Trying to pick up a screw with a magnet pen I buzzed something on the control board. Motor works, I connected a 12V battery to it and runs. Console shows treadmill is running, counts calories, miles, time, etc. Belt won't start though. I removed the control board and checked for melted, burned, blown, leaky pieces, nothing. The board is sending 4V to the motor, when it is supposed to be sending 12V. Help. I'm not an electronics expert, but can desolder and resolder a broken or damaged piece. Just don't know how to find which one it is.

 

Hello there welcome to AAC!
I hate playing where's Waldo!
But this guy looks very suspicious confirm he's not just wrapped up in dust bunnies please! The guy in the red circle.

 

"The guy with the red circle" is the LV SMPS IC supply, Most of these MC2100's use a regular linear supply.
It would be easy to check that the SMPS is working by metering pins 1 & 2 of HD2 for ~12vdc.

@OG's Electronics the voltage to the motor is way higher than 12vdc.
The 12v supply is for isolation purposes for the Console supply.

 

Output voltage was 4.5V.

 

Seems odd the console is still working with a supply of 4.5v?
Remove the HD2 plug, power the motor board and see if it is still 4.5vdc, If it is 4.5 then most likely the SMPS circuit is faulty.
The IC is an odd-ball and is getting scarce.
If necessary you could provide a simple 12vdc linear supply circuit from an off board transformer and bridge to mirror the usual DC supply for these boards.

 

I could do that, but the treadmill would run at a constant highest speed. It varies from 8 to 12 MPH.

 

Not clear what you are trying there??

 

Not clear what you are trying there??

I believe he’s getting the 8-12v line confused with the power being sent out to the walking belt motor. (Hence why he assumed if it was 12 volts on that rail it would be max speed)

but the main drive motor is controlled via PWM from the console (or so I believe)

I think he’s saying power being sent to the main drive motor is only 4.5 volts.

I believe he is having a similar issue to mine where the PWM area is messed up that controls the motors speed.

Since his console is working fine and counting speed and miles and such there is no way it’s 4.5v on his 12v rail.