Toto Drake refills haltingly, then not at all

Hello,
I am new to diy plumbing, so this may seem like a silly question. However, my 4 yr old Toto Drake has been hesitating to refill for a few weeks, and yesterday, didn't refill at all. When I dumped a bucket of water in the bowl to flush, then it refilled...

The water is turned on, and nothing else has changed.


In any case, I'm thinking I need to replace the fill valve? From what Terry says, it looks like I can use a Korky replacement quietfill...

Thanks so much

I have had a few call backs for this problem.
Usually it is a supply tube with a built in "Flood check" but this is usually for new installations.
Another problem is there is a float and ball on the fill valve, if you look at the fill valve on the side is a square box and at the bottom of that box is a white ball. Sometime that ball gets blocked and the water does not drain from the float keeping the float closed.
The only way to fix this is to replace the fill valve.

Thanks so much. I just wanted to make sure that it was the fill valve which was the probable problem, rather than, say, a blocked vent or something.
I'll definitely try my hand at replacing the fill valve.
I really appreciate your response!