PORTLAND, Ore. — Thousands of people who learned through text message, Twitter and word-of-mouth that comedian Dave Chappelle would hold a free show filled a downtown Portland square late Tuesday and early Wednesday.

Chappelle arrived at about 1 a.m. to a surge of camera phone-wielding fans. There was only problem — a small amplifier left the comic inaudible to most.

It's not clear why Chappelle was in Portland, and what led him to Pioneer Courthouse Square.

"I'm not here for money," he told the crowd.

Chappelle is best known for his sketch-comedy program that ran on Comedy Central. In May 2005, he walked away from a $50 million deal to continue the popular show.

Most people went to the square at the last minute, after receiving a text or other communication. Chappelle, who had no security or entourage, said he expected 200 people to gather — not the thousands that stood shoulder-to-shoulder.

Chappelle at one point announced that someone was going to retrieve a better sound system, and would return in 20 minutes. When the man came back, spectators fed power cords to the edges of the square to plug them in. But apparently there was no power.

Though the show fizzled, the mood remained festive and there were no arrests. Chappelle left the square shortly after 2 a.m.