Thanks for the advice I’ll certainly look at that

I have a reverse-engineered schematic if needed.
Max.

 

@dendad The TM motor is a 130 volt DC brushed motor. It will run on lower voltages. I've spun one using an old car battery. They don't spin very fast at that low voltage but they DO spin. Testing it with an 18 or 24 volt battery will prove whether the motor is working or not. However, a short may be hidden at that low a voltage. After all, we don't know the exact means by which it's blowing fuses. We don't know if it's instantaneously or if it takes 2 seconds, 20 seconds or 2 or more minutes. Understanding the fault behavior is going to be as important in diagnosing the problem as the fact that it's blowing a 13 amp fuse.

And on that note, I thought those things were breakers that can be reset.

 

I have just bought a second hand Nordic track treadmill mainly because reviews said they were reliable, however it suddenly stopped mid work out and blew a fuse, we’ve used a drill battery to check the motor and it appears to be ok

I’m quite annoyed as it cost a lot of money and I’ve not had it very long

Can you help

Did you ever get this sorted? Think I have your treadmill, exact same issue, Turns on okay, press the speed arrow blows the fuse in the plug instantly.

 

Most likely the Mosfet device on the heat sink.

 

Remember the tube of silicone oil and Allen wrench that came with the treadmill? Maybe it's time to use it and adjust the mat tension. Friction can strain a motor enough to blow a fuse - easily.

 

I have the exact same problem as described above.
House breaker fuse is tripped when I turn on the belt.
If I disengage the power to the motor incline etc. functions normally.
The removed motor runs normally on a stand alone DC power supply.

I suspect the Mosfet or the rectifier.

Rectifier is a IXYS DCEI30-06A (2-legged)
Mosfet reads GP4063D

Can I check these in circuit, using a regular multimeter?

 

Yes Preferably bench test with a 20hz pwm signal into HD2.

 

What I did not see mentioned was any ground-short resistance checking. That is simple to do WITH THE TREADMILL UNPLUGGED FROM THE MAINS POWER!!
AND certainly the possibility of an increase in belt friction causing an overload of the motor drive is valid. A simple check with the motor removed but connected to the motor driver would reveal that condition.

 

The circuit normally ramps up slowly, so if it is belt friction etc, the fuse does not usually blow immediately. But at a short time into the operation.
Very common is the Mosfet failure.
Easy to check, sub motor for 100w incandesent lamp etc.

 

What I did not see mentioned was any ground-short resistance checking.

Possibly the reason for not seeing any mention of testing in that manor is the thread originated back in 2018. [edit] see post #12 [end edit] It was briefly woken up again in 2022. keewhip again has reawakened this thread. Instead of opening an old thread perhaps you (keewhip) should create your own thread. MY last response in this thread (not counting today) was back on June 25th 2018.

 

OK, I am not in the habit of date-checking every post I read. My error.
BUt still, checking with the motor not loaded would certainly show if it was a load current issue or not.

 

OK, I am not in the habit of date-checking every post I read. My error.
BUt still, checking with the motor not loaded would certainly show if it was a load current issue or not.

No error, thanks for the advice.
I have tested with the motor disengaged from the belt and the fuse still blew.

Instead of opening an old thread perhaps you (@keewhip) should create your own thread.

Thought about that, but since the conditions we're exactly the same, I decided not to.
Keep the information about this problem in the same place for other visitors.

Very common is the Mosfet failure.

I desoldered the mosfet and the rectifier.
Simple diode testing shows the mosfet has failed.

I will post an update if replacing fixed the problem

 

Simple diode testing shows the mosfet has failed.

Common issue with these models,
With the lamp test, you do not see the ramp-up glow, i.e. full brightness right away! .

 

I promised an update so here it is.

I replaced the Mosfet with this one: IKW50N65ET7XKSA1
Connected the board to the treadmill and, Hurah!, the motor started running again.

However...
It felt like it was running a but faster now, 4km/h felt like 6km/h to me.
Tried to set the speed with the potentiometer where it reads speed on the board, but I didn't notice any change in speed.
Returned the potentiometer to the initial position.

Let the treadmill run for 15 minutes and then the fuse blew again, back where I started.

I can get a replacement board on aliexpress for €100.
I am in doubt between replacing the entire treadmill or trying the ali board.
I bought the treadmill new 8 years ago.
What are my chances the problem is in the board?
I inspected the motor thoroughly and it looks very clean.

 

You could remove the motor and test it on a DC supply, and or just replace the Mosfet and run the motor off the TD, i.e., no load for a test.
.

 

Doesn't look like I mentioned it before, but you should always fully diagnose the problem before you start throwing parts at it. You COULD end up with a new treadmill for your fuse.

 

CERTAINLY Tony is correct!! Diagnostics is what a competent individual does (almost) first, right after looking for things like wires come loose o unplugged.
One symptom was already noted: It ran too fast and there was no control. Check to see if the mosfet has failed shorted.

 

One symptom was already noted: It ran too fast and there was no control. Check to see if the mosfet has failed shorted.

Perhaps I wasn't clear in my previous post(s).
It seemed to run too fast, however there was control.
I could change the speed from 2 to 22 km/h and that worked perfectly fine.

I already changed the broken mosfet, but the symptoms (fuse blows when motor turns on) returned after half an hour.
I assume this is the mosfet again, but there probably is another problem that caused the mosfet to fail.

Motor is running perfectly fine on an external power source, no drag, belt not too tight etc.
Incline setting is working fine.

I think the problem must be in the controller board somewhere, but for me it is a knowledge, time and cost equation.
Replace the entire board for €100 or checking all the components on the board which includes desoldering etc.
Sourcing the replaced mosfet with shipping cost me about €15 and over a week to get here.
I am by no means a professional and only have the basic tools for diagnosing et cetera.

This is my diagnosis to opt for a new board

 

Motor is running perfectly fine on an external power source, no drag, belt not too tight etc.
Incline setting is working fine.

First, the incline has nothing to do with the tread belt running.
Second, the motor running "perfectly fine" with no load doesn't exonerate the motor. There's a chance that under load the motor gets hot enough to expand some wire that may be shorting out. To determine if the motor itself is the problem or not you need to put a load on it and run it for at least two hours. Why two hours? Because you're not likely to run a treadmill continuously that long. If it can last that long it should be able to last the 30 to 45 minutes you are probably going to use it at any one time.

Have you disassembled the motor? Is the motor choked with dust from wearing of the drive belt? Don't zero in on just one possibility. The facts that changing the MOSFET resulted in it running but with limited speed control suggests you may have gotten the wrong FET. Or you got a bad one. Possibly something scavenged by some recycler who scraps out used components only to sell them as new.

Did you get your FET from a reputable source? Or did you get it from Flea-Bay? Or Amazon? Reputable versus cheap - if you go cheap you get cheap.

Fully diagnose the problem before you throw any more money at it. Even parts from reputable suppliers.

 

It is very rare to get motor problems on the TM's, But the best way is to remove the main board and test it on the bench, you require a 20Hz source in order to input into HD2 pin 4.
There is a reverse-engineered schematic posted here that covers most, but there are at least five variations of this board, but most have similar circuits and characteristics.