Cam timing is not rocket science and I have so far (touching wood Lol) never had an engine that I couldn't start after doing a cambelt. Although I am not an electrician I have more years than I want to mention as a mechanic (as in, mechanical). I have a very limited number of timing pins and normally rely on drill bits or Tipex. I even use a Renault pin on a Ford for the engines with a floating sprocket. As has been said this is almost certainly a timing issue. Forget scopes or any management issues and get the mechanical bit right. Liam has said that the later crank locking tool didn't seem to fit? I use the same tool for both engines because the timing marks mean nothing as long as it goes back in the same place as before you started (assuming it was running ok). If you get really confused just put the valves for number four 'on the rock' and pistons for 1 and 4 at TDC and it will run. Even if you do have the correct pins etc, on most engines Tipex will give you a good datum to confirm timing when turning over by hand after fitting the new belt. Dave, I fully agree with your comments.
Regards to all.
Bryan.