Hayward multiport..leaking and stuck.

Today i went out to backwash, pushed down on the handle to turn it, which it did about 1/4 turn, and then stopped. turned it back to run position and turned the pump on and a small amount of water started leaking from the top. Pump off, tried to turn to backwash, 1/4 and stuck and not it will not budge.
So, i unscrewed all the nuts and pulled the top off( it was hard to do , but finally came out easily.)
I expected to find something jammed up, but didn't, handle still will not turn, and i am unsure of what to do next.
Any ideas?
Should i replace/lube anything while this is apart?
Going to take this piece to the pool store tomorrow, but thought someone here might have some insight.
Thanks much

Very odd. Before I read the whole post I suspected the spider gasket came completely loose and jammed things up. With the top off, which houses the handle, spring, and movable valve part, does it turn freely? If not then something is wrong with the top part. There is an O-ring seal in that assembly and you can take it completely apart. Never had to do it to mine though but it looks pretty easy. Best I can do for now.
Al

I didnt mention is before in my haste, but when i removed the valve assembly there were quite a few small pebbles( pebbletek pool ) jammed into the gasket on the interior of the valve head, i was able to pick them out. There was some very minor wear damage to the plastic part of the removed assembly...the part that sits low in the valve body. in hindsight i think that the pebbles caused the jam.
Now i think i may very lightly( i stress lightly) sand or file the rough edges that these pebbles created.
Should i lube anything?
The o rings all look good with no damage.
The handle moves now, as much as i can get it to move out of the valve body. I may take it to the local shop tomorrow anyway to have them look at it.

Glad it is probably a simple and obvious problem and fix. Just lube the O-ring(s) with silicone grease. Anything you put on the spider gasket will just wash off so don't bother. When one thinks about it, small stuff can get past the skimmer and pump baskets and mess up that valve.
Al