Nri info

I have a National Rejectors Ind. coin mech. The serial number is 12-80-60. The model number is 08-52-000. Does anyone have a manual or some information on how they work. I've tried cleaning the unit with soap and water, but it only works when I put a dime in it. It is set for ten cents. I put nickels in the tube so there is enough change, but when I try to put a quarter in, it gets stuck or it seems to deposit but doesn't give change. I tried putting in 2 nickels, but they automatically drop into change bin. Thanks.