I see your problem now, you've got a hammer stuck to the flywheel
If I have to use 320-400 sand paper, I use the same area on the paper to wear it down. If you file or sand too hard you remove the hardness coating which is only a couple of thou thick and the points will burn very quickly.
I use printer paper with alcohol on it to wipe the points, a fiber from the Q-tip or the oils on your fingers will make points not work.