Little lost !!! with my cvc-168 5

Let me start by saying i'm a complete novice. Thanks to everyone here I have gathered a bunch of info. I got my cvc-168 5  last week and it's in pretty good shape but i can't get it to take coins or for that matter vend at all. Everytime i put a coin in it falls in the change slot. It has a mars electronics not sure on the model. How do i know if its bad? i took it apart and it seems to have a bumper or something preventing the coins from going down. The bumper has a red wire that is not hooked up? There is also a red light on the right above the price change switches?  I tested the augers and they all work great. "got that tip here thanks" does anyone know where I should start.
Thank you very much !!! '>

I have a cvc 168-5 and had the same problem. I can't tell you how to repair the coin mech but you can replace it for about $30.  I bought mine off ebay and the guy I bought it from consistently puts repaired and re-tuned mars 6200 on ebay. He tunes them to take the new $1 coins as well. Here is a link to one he is selling.
http://cgi.ebay.com/ws....y=25390

Good luck.
Andy