Under the bottom shelf, or at the top bracket, there should be a pivot and an eccentric which when correctly adjusted cause the doors to come to rest in the normally closed position.
Also at the top will be a set screw which captures the shaft which may be loose.
Grabbing the shaft and lifting will tell you a lot.
It sounds as if this eccentric has or is wearing out.
Here is a link which may be of help. Click on any of the models and follow it to the PDF's;
http://www.cabinetparts.com/shop_2006/grouping/?id=199&SID=b0c75b430c57e1be8f09743591a9a0fc

Thanks, snoonyb.

I checked out those PDF's. I couldn't see the eccentric you mentioned in them. They still have a smooth glide, until the edge of the doors hits the frame. Do you think just replacing the whole assembly is the best option? Or if we dissamble the shaft we might be able to find out what has worn? Is the eccentric inside or outside the shaft? The cabinets are 20 years old, and the lazy susan has been heavily used (we keep our pots and pans there), so wearing out a part makes sense.

Some designs did not have a self locating device and depended upon the user to place them at the rest position to allow the door to be closed, or they may be an integral part of either pivot.

Chances are that at 20yrs. you'll have difficulty finding replacement parts.

Because its in the condition its in, I would remove it, discover the cause and take the shaft and pivot assemblies to a couple local custom cabinet shops and also ask the cost of replacement hdw.

Be sure and measure the internal height of the cabinet.

My Partner had some small strainer fall behind the back of the lowest shelf. When I removed the screws the shelf fell and now I am unable to raise it back up to it's original position. Will I have to remove the counter top andthen the othe shelf in order to restore it to it's original position. Any help will be greatly appreciated. Dick

"Will I have to remove the counter top andthen the othe shelf in order to restore it to it's original position. "

Just find the set screws on the collars for each shelf.

My problem is that I can't physically lift the shelf back into place. I have no way to grab the ends and lift it straight up.

what is the shelf made of? can you use suction (like a small plunger) to grab it and lift it up?

Is there a rim or collar at the pole that you can grab with pliers?

Completely release the set screw so it will slide as easily as possible. Lift it enough to put something below the shelf so you can then lift it and set it back in place.

Thanks for your answers.
I came up with a solution. Since it's a very tight fit to get into, I used a Belt. I wrapped it around the shelf and was able to lift it up evenly and secure it back in place.

sounds good. thanks for the follow-up.

We had a similar problem because the lazy susan's steel shaft rested on a plastic base that understandably wore away. We replaced the plastic with a piece of plywood, but now the unit has slid down again, which means the door again gets caught inside the frame. We've adjusted and tightened the screws. Other than taking it all apart again and going to a custom cabinet shop to seek professional help, does anyone have repair suggestions?

Even home depot sells short length of steel flat in various sizes.
Something about 1/8 inch thick and twice the pole diameter wide would do fine.

Cut off a section a few inches long, drill some holes near the ends of the cut off piece.

Put the piece of metal under the pole and fasten it down with some wood screws into the cabinet bottom.

You could put a little wheel bearing grease where the pole rests on the steel.

My lazy susan is also very old, but all metal, so I'd like to keep it. But the bearing at the top broke. Is that too old to replace now?
If I replaced both the bearing and the shaft, would that do it?

"But the bearing at the top broke. Is that too old to replace now?" Is the pole free at the top now? There really is no "bearing" at the top because all the weight is on the bottom. the fixture at the top just hold the pole in position so it doesn't fall over. any similar flange that provides a socket to put the pole in should work fine.

Thanks so much, sdello! My handyman said it was a bearing, and I would need a new one.
And yes, the pole is now free. So happy to know I can just run out and buy a flange!
You rock!!!

As a qualifier, it needs to be snug otherwise it will have some slop to either side. If it's a high end kitchen you might need a brass fitting or bushing in there to keep it tight. Alternately they could have a bearing in there to keep the shaft snug and reduce friction while turning. A flange would certainly work to fix it. A bearing would do a better job.

Here is a variant. My cabinet was sagging as well. I went into the cabinet looking for the set screw and found a large Phillips head screw. Loodened it and was able raise the rig a bit. I then proceeded to try and tighten screw and it just kept turning. After several turns to the right, I rotated the rig and see how it would close and I discovered I had raised to assemblage too high. Come to find out the "set screw" was not a set screw but an adjusting screw that raises and lower the whole rig. A couple of full turns to the left and it fit-up perfectly...sound as a pound!