Thank you for that info.
This is more than likely just a bad drive belt for the doors. Inside there are belts for different movements. This is a pretty easy to to do repair but should be done by an experienced technician, if you are handy and have the tools to get to the belt you could do this yourself with my assistance. Please let me know on that I can locate a source for that belt.
It is a common issue with these units.
Sometimes the motor gets weak but that is rare to say the least.
But if you would like to have this done most local home electronics stores now make repairs on these. And it wouldn't be a bad idea because this part replacement is part of a basic internal tune up and will prevent future more serious problems. Also this one is worth fixing for sure.
If you need help locating a good repair shop please let me know and send me your State and town as well.
In any case, I will stick with you until this is complete.
Please rate kindly thus far, it won't cost you anything to rate my service to you kindly,
Then you can reach me by simply replying to this message anytime.
Thank you and have a wonderful Sunday!