Help with Motor Control Board - ProForm treadmill

[budm]

Re: Help with Motor Control Board

There is Zener diode connected to VDD pin and Ground of that MOSFET driver IC, check to see what DC Voltage you get, again this hot circuit so do not touch anything with your hands or body.

[Crrose]

Re: Help with Motor Control Board

No that is maybe a little shadowing but more of one of the solder joints to that resistor. I'll reassemble the board again and test that Zener.

[Crrose]

Re: Help with Motor Control Board

Ok the zener and that mossfet both tested at 12.1VDC

[Crrose]

Re: Help with Motor Control Board

I also just tested the diodes D9 D10 D14 D15 D16 which all look like they are identical. I get 0 reading in all but D10 which gives me an .5 ohm reading and it has continuity where the others don't. Does that sound right?

It looks like D10 connect to DZ1 and then to the relay.

[budm]

Re: Help with Motor Control Board

So we do have power to run this MOSFET driver IC.
D10: There may be another component connected in parallel with D10, you need to lift one leg or remove it off the board for proper test. Pictures and location on the board?

[Crrose]

Re: Help with Motor Control Board

Here is the picture, located on the bottom corner near where I had the bad zeners.

This is the bottom of the board.

[selldoor]

Re: Help with Motor Control Board

No that is maybe a little shadowing but more of one of the solder joints to that resistor.

Did you miss word/words out of this

[Crrose]

Re: Help with Motor Control Board

By looking at the board the only thing it is connected to is the zener in DZ1 and the one leg of the relay switch.

[Crrose]

Re: Help with Motor Control Board

Did you miss word/words out of this

No that was in response to your question possible shadowing or burn mark on the orange resistor.

[Crrose]

Re: Help with Motor Control Board

Here is another picture of where D10 goes. Not that great but I don't have color printer.

[budm]

Re: Help with Motor Control Board

It looks like generic diode 1N4XXX series, remove and test it off the board.

[Crrose]

Re: Help with Motor Control Board

I removed D10 and it still shows continuity and reads .5 ohms.

[Crrose]

Re: Help with Motor Control Board

Looks like it's 1n4148 diode. I hooked it up to a 9v battery and got nothing so I guess it's shorted.

[Crrose]

Re: Help with Motor Control Board

On my way to store to get that diode and the 2 large wound resistors.

[Crrose]

Re: Help with Motor Control Board

Ok I just got the 2 large resistors, got 10w 1000ohm ceramic. Maybe not large enough cause they measure .831 and the original measure 1.442 in diode mode. I also replaced D10 and now it measures .609 but if I reverse the leads it measures 1.031. Motor still won't turn on.

[budm]

Re: Help with Motor Control Board

So the old two black resistors are both 1000 Ohms for sure?
"Ok I just got the 2 large resistors, got 10w 1000ohm ceramic. Maybe not large enough cause they measure .831 and the original measure 1.442 in diode mode" You are measuring the resistors in Diode mode?

[Crrose]

Re: Help with Motor Control Board

Selldoor in post #145 said it was so that's what I got. However I have a new problem now. I was testing to make sure I still had the voltage from that small 8 pin mosfet and I must have shorted it or something because all of a sudden the treadmill motor just started at full speed. Now it won't shut off except by turning power off, even when pulling out the safety switch.

[budm]

Re: Help with Motor Control Board

The Gate drive stuck high so the MOSFET is fully on when you shorted out the Gate drive IC TC1410, do not run it or you burn out the motor.
So it proves that the drive circuit is OK, you just do not have the drive signal to drive the MOSFET.

[Crrose]

Re: Help with Motor Control Board

So do I need to replace TC1410 now?

[budm]

Re: Help with Motor Control Board

You can remove it and see if the motor will still run at full speed, just do the quick test, if it does then the MOSFET is damaged.