NEF oven and light not working but timer is on?

NEF oven won't work also bulb not working after the electrics were switched off for decorating but the time lights up on the oven so the switch is ok
I have tried pressing the 2 buttons in on timer to reset but this doesn't seem to work also switched the plug socket of and reset but still the oven isn't lighting up or getting warm in any way
Any suggestions please