Hi, I've bought a treadmill 2nd hand. But after an hour of use the fuse blew in the house. Now every time I turn the treadmill on, everything lights up fine, but the second I turn on the belt the fuse blows. If I disconnect the motor, there's no problem but I can measure 280VDC (DK 240V in sockets) on the motor connectors and the motor are 160VDC. So I suspect that it blows the fuses because the motor tries to take off too fast. Normally it would start very slow and then you have to crank it up if you want it to run faster.
I suspect the either the IGBT or the Thyristor is shortened. But I'm not sure anyone know what it could be?

 

Connect a lamp up to the motor leads, it will show if full voltage is present when the motor is energized.
Max.

 

Connect a lamp up to the motor leads, it will show if full voltage is present when the motor is energized.
Max.

Hi thanks for replying. I'm not sure exactly what you mean. Do I disconnect the motor and connect the lamp to the motor? Or to the pcb? I know the motor are working because I've tested it with a battery.

 

The lamp will show full brilliance immediately if the drive turns on full at start.
If the fuse does not blow with the motor disconnected then it most likely is a shorted Mosfet.
Max.

 

The lamp will show full brilliance immediately if the drive turns on full at start.
If the fuse does not blow with the motor disconnected then it most likely is a shorted Mosfet.
Max.

Ah yea off course thanks.

 

Hi again, I just did the lamp test. And the lamp lights very bright the second I start the belt. But its only lit for a second and then it dims until it's completely off.
Any idea what could be wrong?

 

Not sure what is happening there.
Here is a couple of pdf's one has a circuit for driving the board with a pwm circuit when used separately.
Max.

 

Hi, I did some research on the schematic you sent me. And founded out it was the igbt. I changed it and everything worked again. But the motor has no torque it runs fine without any load on the running belt. But when I step up on the belt it stops immediately, and starts again when I step off. I have checked that there's no slip in the drive belt, the rollers or the running belt. And I've also lubricated the running belt to be sure. I'm sure it's an electrical problem, but I can't find out what it can be.

 

Hi, I did some research on the schematic you sent me. And founded out it was the igbt. I changed it and everything worked again. But the motor has no torque it runs fine without any load on the running belt. But when I step up on the belt it stops immediately, and starts again when I step off. I have checked that there's no slip in the drive belt, the rollers or the running belt. And I've also lubricated the running belt to be sure. I'm sure it's an electrical problem, but I can't find out what it can be.

Hey tom i have exactly the same problem with my pro-form 585 perspective did you find a solution ? And i want you to help me by sending me a picture of the original pieces that i changed as u can see but they didnt work i hope you help me man this is my e-mail for better quality of photo
ayarisami2010@hotmail.fr

 

Hi, I did some research on the schematic you sent me. And founded out it was the igbt. I changed it and everything worked again. But the motor has no torque it runs fine without any load on the running belt. But when I step up on the belt it stops immediately, and starts again when I step off. I have checked that there's no slip in the drive belt, the rollers or the running belt. And I've also lubricated the running belt to be sure. I'm sure it's an electrical problem, but I can't find out what it can be.

I have the same problem. The diode next to the IGBT appears like it may be short, HFA25PB60 . Before I go order one of these and try again, it would be great to know if you managed to fix yours.
thanks,
Ivan.

 

You should be able to test it if shorted, remove it first.
It is across the motor, so you cannot test in circuit.