I have a 1995 IGT Jokers Wild coin operated slot machine. It operates fine except the bill verifier won’t accept bills. When I turn he machine on the bill collector cycles so I know it’s gettig power but when I try it insert a bill nothing happens. Attached is the machine and part number. Are there any simple things I should look at? I’m not a slot machine guy and this is new to me. Before I call someone to look at it I thought I would give this a try. Thanks in advance!