I'm a dealer in California for Ketron, Yamaha, Korg, Roland and Casio Arrangers.
One of my problems with all the X series of products was that when you unscrewed all the screws necessary to open the keyboard, if you aren't careful putting back the screws, the plastic would crack where the screws are going into. I always wished they would use metal inserts in the posts but they never changed this. So if a repair shop isn't careful the screws would be left in the wholes without actually going into anything more then a loose piece of plastic and many times I would see keyboards with several missing screws. The good news is that there are so many screws that you might not miss any of the ones which fell out!
In the past I have had more customers with Solton and Ketron products experiencing problems, more so then the other product brands, but not since the SD5 has come out. I think Ketron has learned a lot from past issues and as all good companies do, they learn and make corrections. There used to be a lot of loose connections and circuit boards that would come loose but I'm pretty sure these problems have been corrected over the years.
It is amazing to me that the shop I use for repairs has a sign on their wall that says " all repairs done on Ketron products have no warranty". I've never seen this at any shop before. They only have this posted for Ketron and Generalmusic products. This tells me they must have issues with customers after the repairs have been made or else this sign wouldn't be posted.
Kaye's Music Scene