Treadmill suddenly stopped working and blew fuse

Thread Starter

Vickyg

Joined Jun 24, 2018
8
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
 

Thread Starter

Vickyg

Joined Jun 24, 2018
8
It keeps blowing fuses unless I disconnect the power cables that go from the control board to the motor, if I disconnect it it doesn’t blow the fuses and the console will show the machine working but the actual treadmill doesn’t work, if that makes sense
 

Hymie

Joined Mar 30, 2018
819
13amp that are blowing it was working fine now it blows fuses
So when the PCB in the photo is connected to the mains – all appears OK.

But when you plug in the motor connections to this PCB, the mains plug fuse operates.

Is the above explanation correct?
 

Hymie

Joined Mar 30, 2018
819
I find that hard to comprehend – effectively a secondary fault is causing the 13A plug fuse to operate.

That does not make sense – the PCB fuse F5 should operate well before the plug fuse.

To blow a 13A fuse (within a short time), requires a current of over 20A – so you might have a fault from Live to Earth somewhere within the treadmill.

If you have a multimeter, measure the resistance from Live to Earth (with a good fuse in the plug) – but don’t go blowing more fuses.
 

MaxHeadRoom

Joined Jul 18, 2013
20,675
It sounds as though the PMW components may be shorted, if power is applied with a motor connected the motor that has a large flywheel fitted tries to go into full speed right away and causes an over load.
With the fuse OK with the motor disconnected, the bridge should be OK, try a incandescent lamp in place of the motor and see if it lights at full brilliance right away and if the fuse hangs in.
Max.
 

Hymie

Joined Mar 30, 2018
819
The earths have all been checked and they are fine, there are no internal fuses in the machine
If you take a close look at both sides of the PCB, there is no isolation between the mains input and the motor supply out.

The TS has stated that when this PCB is powered without the motor connected, the fuse does not blow – but powering the PCB with the motor connected causes the plug fuse (13A) to blow.

Therefore I would suggest that a component controlling the voltage to the motor has failed short circuit.

My bet is that it is one of the semiconductors hidden from view (by the two large electrolytic capacitors) – but their solder connections are shown (on the track side photo) at the bottom, where there is an indent in the PCB (circled in the photo below).

I would recommend you check for a short circuit between these solder connection points.

1E622130-8D16-4ECA-A6CD-EB3FF8FC829F.jpg
 
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