Repair diagram/manual for Singer Futura 1100?

I have not used my Singer for a handful of years, but just got it out with a view to re-lining some curtains. I threaded it up, and started to wind thread onto the lower bobbin - and then there was a burning smell and smoke started to appear from the top where the electronic buttons are.

My husband thinks a condenser may have failed through lack of use, but we aren't sure how to take the top of the casing to pieces. Is there anywhere I can get a repair manual or diagram please?