treadmill useable for parts (BT48)

I have a Proforma treadmill. It isn't currently working, although I bought a new belt, motor and motherboard for it but think the person who claimed to be a treadmill engineer did not know what he was doing when he fitted these parts and they may not have been fixed correctly. It is possible someone who knows what they are doing could actually fix it, failing that it could be used for parts.