I have a petrol 2.0i Scenic RX4 and had cambelt done and mechanic didn't tighten aux pulley correctly and it came adrift and took cam belt with it. That's the exact symptom I had, all lights and no fire. DO NOT try and start it, get it checked before you do any further damage.
I am getting my car back in about 1 hour, 16 new valves, new s/plugs, coolant and all the associated gaskets etc all at the workshops expence. I do so hope that renault UK/Europe are better and speedier at supplying parts to non-marque workshops in your part of the world than they are down here. Service my mech recieved from Renault was woeful and I am considering sending them a smarten up your act letter or risk losing customers faster than they already apparently are.
I found out about a very interesting timing anomoly with the 2.0F4R engine too, there is no locating key in the crank/timing pulley from factory
That is why the tension is so important, if the timing pulley isn't held extremely tightly it will move if the auxillary belt pulley comes loose and that spells major disaster.
My wife and I are so glad I didn't attempt the belt change myself and totally f*kc it up because we'd have had to wear the cost and I'd be sleeping with the dog or in aforementioned RX4