This answer relates to the Neff HFT759.
The lamp is only accessible from the outside (top) of the oven.
1. Disconnect from the electricity supply.
2. Remove the woodscrews in the lhs of the door recess which secure the oven into the unit.
3. Pull the oven outwards by about 6 ins. but be careful as the oven is VERY HEAVY!. Make sure that the oven is stable in that position.
4. The metal cover for the lamp housing will now be visible on the top of the oven.
5. The 2 short self-tapping screws holding the metal cover have special tamper-proof slots, BUT the screws have raised heads so they can be easily loosened with a pair of pliers!
6. Remove the 2 screws.
7. Lift the metal cover vertically off the oven, taking care not to damage the insulation fixed to the underside.
8. Unscrew the lamp.
9. The lamp is a 40W SES Oven lamp. I had no problem obtaining one at my local hardware store. This lamp is found in many ovens from many manufacturers. Be sure to get the OVEN version, as there is a very similar lamp used in some conventional lighting units.
10. Install the new lamp and reverse the above procedure.
NB: Securely re-fitting the metal cover for the lamp housing is essential, as it not only provides heat insulation but also prevents harmful microwaves escaping from the oven.
David
January 2009