I've been googling this and it seems like a common problem on the early wii's but I've not found a satisfactory answer.

The wii accepts the disk and loads it into the correct position. Both the sensors on the small board on top of the drive seem to trigger like they are supposes to and the disk sits in the loaded position but does not spin the disk and instead ejects it. There are no unual sounds or crunching and all the plastic gears seem to be spinning around as would expect them too.

I have also checked the n-fuses and there are both fine.

Any ideas on what to check next?

Thanks

Could be the laser. If it's unmodded, I'd recommend getting in touch with Nintendo, especially if it was a common problem.

Yeah I think thats what mind end up happening. It isnt actually my wii, I friend has given it to me to mess with before they fork out to have nintendo fix it.

Is it all discs this happens with? I'm assuming so by the sounds of it, but I thought I'd ask

yes all disks, including GC disks act in the same way - get to the bit when they should start to spin and come back out again.