[GregK]

Hi,
That is a possibility ...... another one might be that you have a short circuit in the wiring, so I would check each piece of wire for damage or pinching, solder blobs touching or very fine slivers of wire touching.

 

[GregK]

Here's what a well toasted NO mosfet look like.
View attachment 9321
Next to this is another mosfet marked PO3, this can blow as well.

 

[GregK]

QUOTE I have just fired up the track today, put that same car on the track and the motor now just seems to run at a very slow speed (not enough to make the car move though) and will not respond to the controller.
This can be due to a bad controller; I had one and the motor would drive the back wheels but only if you lifted them off the track. It made a low pitched humming noise.

 

[GregK]

You can check if the LED is working by looking at it with a digital camera with car placed on a powered up track. Also make sure that you connected the LED the right way round when you extended the leads.

What is the max RPM of the Slot.It P4 ........ a Scalextric chip will just about cope with 20k.