Radio stopped working

Standard factory fit or an aftermarket one?

Generally with car audio there will a permanent live which keeps the memory, the switched live from the ignition which powers the radio's normal functions up usually when the ignition is switched to the accessory position & beyond and a switched illumination live which feeds from the lighting circuit.
Identify these on your connector & verify all are working - a multimeter on volts will do.
Also check the earth is working.

If they are & the radio is still not switching on the fault may lie in the radio.

Depending on you confidence you could test off the vehicle with a battery or find a local ICE specialist who can test it for you.

Some radios have a fuse in the back, others you have to take the lid off to find it. Some might have an in-line fuse.
It sounds like the permanent 12v is working but it's not seeing the switched live. Check if (probably the red wire) gets 12v switched with the ignition

It will probably need the security code entered as well.

Thanks for all your replys ill give all a try. An yeah I will have to put in the radio code can I just add this I needed my key code as I was locked out of the car an the immobiliser wouldn't turn off an I didn't have the code for it. Rang landrover Wolverhampton expecting to have a right game as the car is on a 52 plate they couldn't have been more helpful ive just got to show my v5 an prove who I am an they will give it me for free as its on their data base.