I've tried number 1 and 2...i'll try 3 as soon as I can. You mean just hit the reset button on the back?(the one you need to hit with a toothpick?)
Yes, the little tiny button thar.
Just remember that it will kick everyone off the router, and reset all default settings (I.E. your WEP key will get changed back to the default and stuff).
You will have to re-log-on to your router and fix your settings to work right again.
If that doesn't work then your router is probably broken.
And another suggestion: If your router is plugged straight into a wall outlet, get a surge protector for it. Do this especially if you live in a stormy area and stuff. A surge protector can save your router from frying due to power interruptions.