My Ryobi PD750 impact drill just stopped working! Is there a safety button or something that could prevent it from working? Ive tried other plugs. Its fairly new.

try e-bay
enter brushes for ryobi electrical equipment

I would spray a little bit of WD-40 while pointing the bit up towards the sky. The fit is very tight and any rust can jam the bit. When the tool is stored properly to prevent rust and used regularly this won't happen. If I'm going to use bit with rust I wire brush it first and then put a drop of oil on it.

Put the bit in a vise and try to turn the drill to release the bit. You will need to put a wrench on the area of the drill that's holding the bit and do the turning by the wrench.

don't think there is much to it. See page 4 in this manual

http://www.ryobi.com.au/Ryobi/files/e0/e029b72d-32ec-4e92-a555-2a3caac4fa92.pdf
Pull the chuck out to unlock it and push the drill bit and chut back in to lock it.
Hope this helps.

The battery problem, buy new Ryobi batteries.

OK, try to grab the chuck tightener and loosen by pressing lightly on the drill throttle button in whichever direction it takes to undo the stuck in drill bit.

I do this all the time.

Just keep it on high, vari-speed on an impact driver is not very useful unless working with delicate materials.

yes, most chargers have internal fusses.

something is wrong. take it back if possible.

Round bits are not compatible with the Ryobi impact drivers. You need the hex shank "quick connect" bits and accessories. There is an adapter available. it is basically a regular style of keyless drill chuck with the quick connect hex shank that should fit right in to your Impact.