A good way to create usable storage space from deep corner cabinets is to install a lazy Susan corner cabinet. A lazy Susan cabinet may develop some minor problems that need fixing now and then. Fairly simple adjustments usually are all that is needed, especially if you understand how the pole and shelf hardware are designed.
Remove everything from the shelves.
Remove everything behind or under the unit and vacuum all dust and crumbs.
Check the center shaft to locate the bolts or screws that vertically anchor it in place. These are found at the top and bottom of the shaft where it is fastened to the cabinet. The center shaft consists of a rotating sleeve and a rod.
Loosen the bolt and straighten the rod and sleeve. Use a level to check the vertical alignment. Tighten the bolt.
Try to turn the lazy Susan. If it turns but binds when you add weight to the shelves, parts of the shaft may be worn and need replacement.