If you have the normal OV Chipkaart issued by the GVB, it won't actually work on the trains until you set it up at an NS ticket machine. You hold your card to the NS ticket machine reader and then it gives you various options. It should say something like "You are not currently set up to use the train" and directs you to the menu option that sets up the card for train travel (all they want you to do is select whether you will be travelling around in 1st Class or 2nd Class).
From a recent thread:
Quote:
If you want to use your OV Chipkaart on the train, you then have to go to an NS ticket machine and set it up for travel on NS (which is not that hard, basically you just tell the system if you want 1st Class or 2nd Class). The card is then permanently set up to allow train travel, and you check-in and check-out at the end of every journey on the readers. The only snag is that there is a minimum balance before you can use the train, I think it's officially €20 although someone mentioned that the actual amount might be lower. So you end up with a lot of credit sat on the card when you come back off holiday...or you forget to check-out at the airport and the system assumes you've travelled across the other side of Holland and deducts €20 or something silly.
I can't find the thread where someone was talking about the minimum balance accepted by the gates being less than the official €20 for train travel.....so I'd assume it really is €20 until someone gets concrete evidence to the contrary.
