Elektron Musical Instruments

Hello everybody!
I bought a broken sidstation... I know... it doesn't sound like a bargain, unless I can bring it back to life!
When powered up, the three led light up (and stay like that), and the display just doesn't do anything.
I haven't tried anything else because, it is evident to me it's not functioning properly.
Do you have any suggestion on how I could fix it? (I have a multimeter and can have an oscilloscope)
I would appreciate on where to start from. For example which component check first, and how....
Thanks in advance for any help in the form of advices, information on where to find service manuals/schematics, replacement component...
I really hope I can make it sound again, as I felt in love with its sound (I love the pads and the leads)!

Kind regards,
Marco