For the most part ovens are usually quite simple appliances, there are not many things that can go wrong with them.
If you are endeavouring to diagnose a fault with your cooker, please remember to keep yourself and your family safe by following our basic safety guide.
If you intend to work on an electrical cooker, you need to ensure that that cooker has been isolated from mains electrical power. You should do this by ensuring that the power to the device is off by locating and switching off the isolator switch. Normally found near to the appliance on the wall. In the event you can't find the cooker's isolator, you should isolate the power at the house-holds circuit breaker (or RCD).
When isolating the appliance from the electrics, you need to ensure and test that the appliance is off by operating the oven or checking that the cookers clock is blank. If they cookers clock is on or flashing your appliance still has power.
If you have a fault with gas cooker, work should be carried out by a suitability qualified engineer complying with your local laws. Within the UK, engineers performing work on gas carrying components need to be registered 'Gas Safe', you can look up Gas Safe engineers in your area on http://www.gassaferegister.co.uk/