I found some time to work on the treadmill.
Made some test with the motor connected and the MOSFET IRFP250 burned again.
This MOSFET is rated 30A. What could cause the amps to go that high?
What could I test to find the faulty component.
In the documentation for the board, it is stated that the board would not allow the amps to go high enough to damage the circuit and will go in fault mode with the diode flashing.
When I plug the motor to a car battery (running 12 V) and I hold and stop the belt, the amps goes to about 30A.
Is that normal?
Thank you for your time.

 

Perhaps the running belt is too tight, causing too much friction in the rollers. Or the bearings in rollers themselves are shot.

 

That current would be normal with an automotive battery and stalled., try running it without the belt, the only thing is you lose the belt tach as it goes up to the console for correction output.
Is the belt sensor working?

 

I dismantled the belt to check the bearings. They were OK, freely turning.
I reassembled and I would say the belt is now rather low than high tension.
Were you able to repair your board?

 

I will need to reorder a new MOSFET in order to make more tests.
To burn the MOSFET is it that the current is too high on the drain or could it be that the voltage on the gate is too high? I try to understand why they burn one after the other. The 2 times I burned the MOSFET , this happen when I run the belt at high speed. When I start at slow speed everything seems to go normal. then when I slowly increase the speed, at some point it just burn and the belt stop and the led flash.

 

Have you tried running without the belt? even if you go to full RPM, these motor do not draw alot of current at high RPM off load, I use a substitue PWM signal controller to run them on the bench where I can bring them up to high rpm under control.
Plugs into the HD2 socket.
Max.

 

Were you able to repair your board?

No, I haven't had time to get into it more deeply.

 

Have you tried running without the belt? even if you go to full RPM, these motor do not draw alot of current at high RPM off load, I use a substitue PWM signal controller to run them on the bench where I can bring them up to high rpm under control.
Plugs into the HD2 socket.
Max.

I think I did on the second MOSFET, tried first with a lightbulb, then with the motor without belt, then install the strap and raised the speed gradually until it burnt.

 

My apologies for resurrecting this thread. I had a power surge through my home killing some equipment, one being my treadmill, sorta, the incline and LCD screen functions still, but selecting a speed and nothing happens from the motor. I've pulled the board and see it is this MC2100LT-12 ICON 2006, and I have been examining and testing, finding damage. I can clearly see the blue MOV varistor has blown. I also can see D1 and D2 have blown, they appear to be SOT-23-3. What kind, there isn't much left of them to tell me. I can see the other are all marked different on top (2XZ, KE1, A4) As for D1 and D2 they are only fragments now. I was going by s-manuals/smd to try and identify some of these.

I've included some pictures of what I am looking at. If anyone can clue me in to what these possibly are or find out from theirs, I'd rather attempt a few dollars of parts before spending hundreds on a new treadmill. Any assistance would be greatly appreciated!

Thank you and best regards!

 

I may have one of the SMT boards on hand, I will check on the morrow.
I assume the LED is not on or is it flashing?
There are at least five versions of the MC2100 boards.

 

I may have one of the SMT boards on hand, I will check on the morrow.
I assume the LED is not on or is it flashing?
There are at least five versions of the MC2100 boards.

No LED while it was connected and testing the other functions, I suspect it also got killed in the power surge. Under the board under the MOV1, two traces on the board burned off so I get to bodge wire them.

 

I don't have one exactly the same, those components appear to be in the area of the 5v regulator, there is a LV supply fed from the small transformer and also a regulator fed from the incoming DC via a dropping resistor, the latter applies to the components shown blown.
There is a reverse engineered schematic I posted here if you do a search, although the component ID's do not correspond to yours, the circuitry is very similar.
The operator panel is fed from the transformer supply, you will need to see if this suffered also.

 

Hello. Not a professional or even hobby circuitist here. Sorry for the thread resurrection but I have the same problem as listed in this thread. I have the Icon MC2100LT-12 controller board in my treadmill. Everything but the belt has power and runs (it even gives a little start then stops).

The R-21 resistor on mine looks to be blown. There are two pictures of the exact board in this thread but I just can't tell what the color code bands on them are. Can someone make them out or point me in the direction of a better picture. (I can't even really tell the differences in color on the non blown ones on my board. I'm not color blind but they are really hard to make out.)

I'd like to try replacing that resistor but i just can't tell which one I need to get. One of the end bands is green and the other end is brown or orange I think but I'm not sure. Definitely can't tell what the middle 3 are.
Thank you!

 

510 Ohms

 

Thank you very much! Appreciate it.

510 Ohms

 

I'm sorry. I have one more question. There seem to be .25, .5 and 1 watt resistors for the 510 ohm resistors. Which would be appropriate for this control board?

 

The original appears to be a normal 1/4w resistor.