I have no experience with your machine specifically but I suspect it's time for a tune up - which you have scheduled. I'd be devastated if my Viking 950 was giving up the ghost...I love this machine.
Yes, new machines are expensive. Given that, if I needed to sew, I do have my featherweight and if push comes to shove, could get the 66 up and running. Granted, I'd hate to give up some of the features of my computerized machines but the old girls just 'keep on ticking'.