Help with Motor Control Board - ProForm treadmill

[Crrose]

Re: Help with Motor Control Board

When I checked the black, white and red wires I get 7v red/black and 2v white/black.

[Agent24]

Re: Help with Motor Control Board

The black one broke in half when I tried to remove it from the board

That's a sure-fire way to know it's bad

[keeney123]

Re: Help with Motor Control Board

You will still need to check that the black, white and red wire connections. making sure you are getting the +5 and -5 volts speed control coming into the SCR board that is really a Mosfet board. I would think that these voltages turn on the gate of the Mosfet. If the mosfet is driving the motor there should be at least either the source or drain with the high DC voltage on it.

[Crrose]

Re: Help with Motor Control Board

I will get back to this tomorrow, been fiddling with it since 7:30 this morning.

[budm]

Re: Help with Motor Control Board

I am looking for resistance not of the resistors, but the Voltages sure look kind of low.
BTW, you can also check the DC Voltage of the MCU ST62Txx between PIN 9 (Vdd) and pin 10 (Vss) to see if it has running Voltage (around 5VDC).

[selldoor]

Re: Help with Motor Control Board

How can I test the Bridge rectifier and the big caps with the board removed?

You can test the bridge like a double diode should have 4 pins 2 AC and 2 DC.


Bridge rectifier test when pins are in a straight line +....~ ~....-

a) put your multimeter in diode test mode
b) put your red lead on plus + DCpin side and the Black lead on adjacent ~ AC pin - record reading
c) reverse the leads - recording reading


Then repeat the test on the other two pins

b) put your black lead on negative -DC pin side and the red lead on adjacent ~ ACpin - record reading
c) reverse the leads - recording reading

Then for good measure change meter to ohmsq200 test the two middle pins
(AC pins) for shorts


You cant test the big caps with the board removed if the heatsink has to be detached to remove the board. Is it possible to securely solder insulated wires to the cap legs (joints) then reassemble and carefully test to the end of the wires

I am off to bed now - early start tomorrow!!

[Crrose]

Re: Help with Motor Control Board

I get 50v on inside and 35.6v on outside one.

[Crrose]

Re: Help with Motor Control Board

Never mind, I thought you were talking about the large caps.

[Crrose]

Re: Help with Motor Control Board

I haven't tested them yet because there is a mounting place under the board that I have to remove to get to them.

[budm]

Re: Help with Motor Control Board

So what resistance do you get on that resistor sitting above those two Zeners, and the other one next to it?

[Crrose]

Re: Help with Motor Control Board

How can I test the Bridge rectifier and the big caps with the board removed?

[Crrose]

Re: Help with Motor Control Board

Yes, 6.6 on the 15v now.

[selldoor]

Re: Help with Motor Control Board

I also just tested the red and black wires that go from board to motor and not getting any reading at all but I do have 121.9v on AC1 and AC2.

From the AC it goes to the rectifier - BR1 comes out of there at around 160v
and on to the Big Caps so if no voltage at the Caps it could be a problem with the BR1.

[budm]

Re: Help with Motor Control Board

DZ1 15V Zener and you are getting 6.6V

[Crrose]

Re: Help with Motor Control Board

I get 6.6 and DZ1 and 24.2 on DZ4. I can't test the filter caps with it hooked up to the board due to the mounting frame being in the way and if I remove it then the heat sink will not work.

[selldoor]

Re: Help with Motor Control Board

How would I apply 24v externally to the relay?

I was thinking you had applied 24v to the motor to test it - I see it was 18v but
that might also be enough to test the relay. Or perhaps a 24v printer adapter?

[budm]

Re: Help with Motor Control Board

What DC voltage do you get on the two legs of each Zener Diode you just put in.
The DCV on those two filter caps should be around 160VDC (measured right at the two legs).

[stj]

Re: Help with Motor Control Board

you may find that the 2 terminals that connect to the motor look like they are shorted together on the meter.
that's called "static braking"

[Crrose]

Re: Help with Motor Control Board

I also just tested the red and black wires that go from board to motor and not getting any reading at all but I do have 121.9v on AC1 and AC2.

[Crrose]

Re: Help with Motor Control Board

How would I apply 24v externally to the relay?