This is in upstairs bathroom in condo. Wife dropped earring down sink. I shut off the water under the sink, removed the ujoint, flushed water through and got the earring to appear. I screwed everything back together, turned the water back on and now I have virtually no water pressure at all, just dribbles out.

Try removing the aerator on the spout. Sometimes turning the water off and on realease some deposits up and the screen catches them and slows the water pressure down. Just unscrew it and rinse it out really good. Also turn the water on while it's off and see how your pressure is. If no water pressure still than your shut off valves are bad, there not opening the valve all the way when your turning the handle, it's common. Good luck to you.

Excellent advice by Diva, She is correct, the first thing you must check is the aaerator.. However if removing and cleaning the aerator screens doesn't get it We will need the brand name of the faucet6. Regards, Tom