Saab won't start!

Saab 93 TD 1.9 (automatic) belonging to a mate who's been staying here a week or so. Hasn't started for a couple of days, but the last time it started without any problem.

It turns over fine but isn't making any attempt to fire up. Battery is good (also connected starter cable just in case), has 1/2 tank of fuel, just doesn't want to start.

Have tried disconnecting the battery in case something needs "resetting". No change.

Grateful for any suggestions .

Cransaft Position Sensor - common Saab failing

It's this. Borrowed a decent code reader from my mate - not showing any revs when cranking.

Thanks to all who replied.