I have to say I was surprised to see you can still get spares, based on the age.
The face spares are available from here, would suggest your issue can be fixed.
There could be a number of issues, an internal fuse, faulty transformer\regulator, but all the parts look reasonable so you should be able to get it fixed for around £100 including parts and labour.
You will see from the parts diagram here, everything an engineer needs is accessible via the AEG page, and from looking at the diagram this isnt an overly complicated device, so I think this should be something which can be fixed, and is worth doing.
Please let me know if I can be of any further assistance.