Guys.

Hope you can help me out.

My daughter drove her lancer home from work, parked in the driveway, went to go out later and couldn't start it.

Lock/unlock works off the key fob. All dash lights come on as normal in the on position.

When you turn it to start, nothing.

The car has 124 kms on it and has been absolutely faultless, until now.

It is a 2010 Lancer ES auto.

Any advice on things to check would be a huge help.

In Park? In Neutral?
Turn the key to "start", then move the gearstick through the gate in case the interlock switch has gone bad.

Could just be the battery has suddenly died. Multimeter test?

Thanks Max, tried all that. Battery still has good voltage. Moved the selector through all gear positions. She did say she dropped the key, but the central locking and remote boot release still works fine.

Could it be the transponder in the key? Do these give problems?

The transponder doesn't get damaged easily as it is encased in plastic - the car would crank, but not fire. Use the second key to test, anyway.

Checked all the fuses?

Try:
(1) Turn to "start", hold it there while you wriggle the key around. If it suddenly fires, it is the ignition switch.

(2) Turn headlights on, then turn to "start". If no action and lights don't dim, it is the starter. Give it a gentle tap with a hammer on the solenoid in case it is jammed.

(Can't remember where the starter is on one of those. Got two Lancers in the driveway, at 40K km and 30K km - too young to have developed any problems yet. lol)

(3) If the starter is easily accessible - bridge the large contact with cable to the battery to the spade connector - this bypasses ignition switch - if it cranks, the starter is ok. (Handbrake on, in Park for safety).