Welcome Sam. Some of the older Bosches had a problem with sawdust getting in the switch. If yours doesn't have a plastic cover over the switch then that might be a possibility. A broken wire in the cord might but if you move the cord around with the router on it should make contact occasionally. It might be the brushes. Check your parts schematic for how to get to them. It might also be the electronics. For that you probably need to take it to a repair shop and let them test it.
Someone I consider a master woodworker once told me that a master woodworker is not someone who never makes mistakes. He is someone who is able to cover them up so that no one can tell.