Help diagnosing single price 80s Cavalier issue

Hi All!

My kids bought an old Cavalier machine a year ago, and operate it at my work. (it had been there for 7 years previous - they bought it from another employee's son). It has recently stopped vending. It accepts coins, can make change if you over pay, but nothing vends. The coin mech does register a credit, and the inside counter increases by one.

I had a repair guy come by, and he thought the vend and credit relays needed to be replaced, but had no source for them. I also think the machine is older than he is :)

I'm now trying to diagnose myself. Currently, once the credit is registered, the vend relay is engaged for only 1/2 a second. Is the vend relay supposed to stay engaged?

I'm sure the behaviour of the single price, relay based machines is somewhat similar between brands? What behaviour should I be witnessing if they are functioning properly?

Thanks for your time.

Ryred