You might be able to detach the coil wire at the coil and set it up in a way as to be able to see if it sparks while cranking. ??? Try to locate the wire end 1/2" away from the coil (held in place with pliers or something) and try to turn the key by reaching in through an open driver's side window while looking at the coil wire end... Tough, but I've done this with my 240. Dunno if possible with a 940. An open spark test so there is a fire risk to be aware of.

You could also do the old school fuel check trick of disconnecting the fuel line and putting it in a jar. Crank for a short bit and see if fuel shot into the jar. Very obvious fire risks with this so pretty much a last ditch fuel check effort.

No firing at all? As in rough firing in wrong order?
I'd think most timing belt misalignment issues should have at least a brief rough firing...

Did the rotor get realigned during belt install?

My guess is an electrical disconnect somewhere you just haven't spotted yet.

Good luck.