Try Don Boomer's suggestion first, Stefan...
But your shop should still be able arrange repairs rather than spending more for a whole new system, indeed they'd be compelled to do so if the system is still under warranty.
Having said that, I bought an "extra" XD-V75 to go with my existing eight XD-V70's and heartily recommend not only its extra features and mic models (if you like the 767 model, you'll doubtless appreciate the V75's addition of a model based on AKG's D5) but also its "future-proofing" USB upgradeability via Line 6 Monkey.
It's well worth the relatively small additional cost.
(Click on my pink avatar for details of my location rig.)