I have just baught a second hand belling double oven cooker, we have switched it on and the timer is constantly buzzing! And the top oven and grill don't work! Any ideas on wot could b wrong?

does the grill work? even if it does you need an engineer. the cooker will need to come out of the unit and the wiring and controls will need to be checked.

First things first. The top oven lights ONLY come on when the top oven is switched on. Operating the grill DOES NOT turn the lights on. If you wish to see what you are grilling, you have to turn the top oven control knob on to its first position as well as turning the grill on.
Secondly, the grill only works when the door is open. The grill does not work when you shut the door. When you open and shut the door, you should be able to hear the microswitch operating. It is located in the right hand side of the cooker, between the inner and outer panels - you cannot see it. I haven't seen the switch first hand but they normally come with an arm that contacts the door mechanism and the door mechanism operating, causes the arm to move, which causes a button on the switch to move and make the circuit. It has been known for the arm on the microswitch to bend with use so it no longer works correctly.
If you have checked all above and you hear the switch operating, then it could have failed. They are quite common, so if you can't get one from STOVES, try espares or someone like Maplin or RadioSpares.
The get to the microswitch you have to take the oven out of the housing and then take the right hand panel off. You should then be able to see it and check its operation.
All the best

It's either the thermostat / switch or the timer unit. Make sure the timer was not set to have turned off the grill first
.
http://www.espares.co.uk/part/cookers-and-hobs/thermostats/aeg/p/1604/143/0/0/1061574/top-oven-thermostat.html

element

If it has a timer, then make sure it is set to manual, and not auto, otherwise the oven will not come on.
What usually happens is, if you have a power cut, or switch the oven off, then the timer automatially goes to auto when the power is on again.

Please rate my solution.
Thankyou.

If the elements 'look' okay, they probably are. The 'infinite control switch' is probably the problem. With out the use of a meter, it's guess work. Unless you can see a connection problem.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/craig_3fa289bf857b1a3c

keep turning the oven/grill selector past the temperature settings, it feels like it won't go any further but it does!

Hi, switch off the mains for the cooker, wait for about 15 seconds then press the 2 buttons on the left and hold them, and then press the - or + button to set the time.
Cheers

Pull off bottom knob of oven shine torch down at 45degrees u will see a red plate turn off power suply and use a small screwdriver to push the plate turn power back on job done.PS Check all vents are clear to stop it over heating good luck.

I found the following information useful, although it wasn't a belling cooker the controls appeared to be the same. Go down to the electronic timer section. http://www.prestigeappliances.com.au/owner's-manual.shtml