Can you tell me how the breakdown occurred? Were you driving and the engine stopped or was it that it just wouldn't start one day?
it would not start one day.
The first thing to do is go back to basic checks.
1. Check there is a spark from the spark plugs.
2. Check there is fuel under pressure at the fuel rail and injectors are working.
3. Check cylinder compressions.
4. Check the timing belt has not slipped.
If all above is ok, then next is to use a scan tool to read the live data from the engine sensors when the ignition is switched on and then when the engine is cranking to see they are registering changes.