Opening seized (?) brewing unit on AEG CF 220?

After cleaning brewing unit following instructions in user manual (though white lever mentioned does not seem to exist - big red contraption to be rotated to open) the cleaning light was still flashing. Removed brewing unit again but now not possible to open; seems to be jammed somehow and cannot rotate red thing. Also, when reinserting the brewing unit the black plastic 'fork' at the front sticks out too far and the service panel cannot be closed. As the red rotating mechanism (two parts and a spring) was retained only with a small circlip I removed it in case this was jamming but even with this removed the brewing unit cannot be opened. Cannot find a service manual anywhere (except a USA service asking for $50; too much without knowing if it would help) to see what can be jamming. Any suggestions? Thanks, RL