Ford Mondeo 1.6 Petrol 1998 won't start?

Hi,
anyone out there with any inspiration I would love to hear from you!

My Ford Mondeo 1.6 Petrol 1998 won't start. Upon turning the key I can hear the starter motor go but that's all that happens.

My mechanic tells me he has changed out the fuel rail, tried a new air mass meter, put in 2 new thermostats but to no avail. Next he's checking the compression of the engine.

I don't know where to go from here. Is it worth continuing with all this?

Any ideas would be appreciated!
thanks