Hi Haasje,
I can help you here if you still need a schematic - and a generic manual may be found on the web. Note - there are 2 (maybe 3) manuals available following major circuit (and PCB) changes.
I have schematics for the early models and are in A0 (dyeline) size. I will have to separate & reduce them - you will have to 'join' them together !
I have later schematics and they are paper copies and not the best quality, but can send you a copy. With the dyeline prints as a 'helper', it's not difficult to figure out part numbers etc in the poor quality schematics.
This will take a week or so to organise and I'm located in Canberra, Australia. Please PM me at: VK1LL@iprimus.com.au
Tell me what your problems are and I may be able to help you as I know these devices quite well.
Regards,
Kit