[Juho L]

Hmmm... I think this is the annoying keyboard controller issue. Went through that crap with my kB years ago. Some of the kB's and Indigos had faulty keyboard controllers which led to mysterious problems like really loud error noises, notes cutting off, lock ups and - like in this case - recognising the unit as a desktop model.

Although there is a chance that there are connectors loose, but I'm afraid it's the case of faulty keyboard controller. In that case only solution is to send it to Access' licensed repair. On the other hand if the unit posessed faulty keyboard controller, then why the previous owner hadn't had it repaired?

Have you contacted the previous owner about this issue? If I'd be you I'd either try to get the deal obsolete and get your money back or make the seller pay the repair costs.