Could be a bad coin acceptor or need tuning, couple of things to try if you contact me I can walk you throught the process

Phoenix Vending Systems
888-858-8583

The Coinco 3340-3341-S single price coin changers are know to have coin acceptance problems, mostly dimes and nickels. Make sure the coin path is clean. There are several things that you can do to effect the coin acceptance, but the most basic thing is to clear the memory (this is the portion of the software that stores the calibration of coins. After you clear the memory it will retore to factory specifications) Set all of the price switches to the “OFF” position. With the power turned on press the coin return lever down 20 times, reset the price and try to see if it accepts all coins. If this does not work please contact me and I can explain how you can tune and calibrate this coin changer. The tuning of the 3340-S series can be done.
Replacement options are a Coinco 9360-S or Mars TRC-6800H that can be purchase with a warranty for $35.00
Phoenix Vending Systems
888-858-8583

If you still want to use the MAKA 27 volt bill validators the may be old but can still be repaired. We can also take your MAKA NB11-B 110 volt bill acceptors and convert them for you to a 27-volt system. You need not look for that hard to find 27-volt unit, just send it to us and we can convert it. Sorry but we can not make them take the New $5 bills.
Phoenix Vending Systems
888-858-8583

If it just an older single price vendor. The changer will have a set of price setting dip switches. They will starting from the left to the right (turned on “up”) be 5/10/20/40/80/160/$3.20 and any combination of “UP” turned on switches to reach the desired selling price. Some older single price changers may not be capable of connecting a validator to.

If it just an older single price vendor. The changer will have a set of price setting dip switches. They will starting from the left to the right (turned on “up”) be 5/10/20/40/80/160/$3.20 and any combination of “UP” turned on switches to reach the desired selling price. Some older single price changers may not be capable of connecting a validator to.