unable to start X on display :0, but :1 and :2 work
 

a few days ago my gentoo desktop froze. i had to hit reset. now if i run "startx", i just get a black screen,and if i "ctl-alt-F1", i can see x is not accepting connections.
if i go to a different terminal, i can kill xinit with killall -9 xinit, and then I can startx with startx -- :1

I looked for an X lockfile, but i don't know where it should be.

Have you tried using locate to find it???

nevermind, i got it. I was just mistaken about what the lock file name would be. it was .X0-lock. I don't think i looked in tmp either, which is where it was.