I just bought a violin off ebay, and I can't get any sound out of it! I tried tightening the strings, tightening the bow, and putting rosin on the bow. Please help me!!! As soon as possible!!! Thanks!

okay, if the strings are tight enough, even if they are out of tune unfortunately it should make a sound, and if the bow is brand spanking new then you'll need to put loads and loads of rosin onto it. if you've alreasy done this then there is something stopping the violin from resonating and letting out sound. look through the holes on the top of the violin and see if there is a cylindrical piece of wood on the inside around the bridge area. this is the sound post and this helps give the violin sound. if there isn't one there you have just been ripped off, sorry. these cannot be fixed as the violin will never sound the same again. i really can't think of why your violin is making no sound, but generally there is something to stop it resonating. are the f holes clear? are there f holes?
i really suggest asking someone in person like a teacher or at a music shop and take your violin with you.

Ok, thanks a bunch for your help. Rosin helped; violin is really cheap, I will take it to a shop tomorrow to get help with it.
Thanks!