Why does faucet work one day and not the next?

Question

This American Standard faucet worked yesterday. But today, water barely trickles from it. I can rotate it just fine and when I rotate it shut, the trickle stops. My gut feeling is that it catches in one rotation direction but not the other. Water from the adjacent sink flows fine.

Questions

1. Why would what seems to be a perfectly good faucet no longer work?
2. I've removed the bolt from the center but nothing comes loose. How do I disassemble it?
3. Any suggestion on how to get water flowing again?

Answer 1

2) The knobs should pull off. They may be glued in place by mineral accumulation over the years; try wiggling them to break that free.

1, 3) Depends on the type of valve; several are in common use. You won't know what you've got until you have it open.

Answer 2

If you absolutely cannot remove the valve and you suspect debris, then remove any fixtures aerators adjacent to it and then figure out a way to pressurize the fixture you deem blocked...blow that stuff right out. Will it cause more damage than good? Likely, but we all had fun now, didn't we?