ATM in Berlin

Did he contact the bank before he left to advise them of his travels? If not, he needs to contact them. Many banks block foreign transactions unless you specifically report your travel information to them.

Laura's right. I've never encountered an ATM in Europe that didn't accept PLUS network debit cards. Your son needs to call the customer service number on the back of his card. No doubt his own bank back home has put a block on his card.

It has to be his card and not the ATM. Almost all ATMs take both Mastercard and Visa and are located on every other corner. I would say all except someone can probability find an exception.

We did speak to the bank twice but I will call the again. I Just wanted to make sure ATM machines in Berlin Germany do take his card. Thanks for your help.

is his secret PIN number only 4 digits, all numbers?

This probably has no relevance to your son's case, but the STAR ATM network exists only in the US, Canada, and the UK. But if your son's card also has a PLUS network logo, he should be OK as long as there's no block on his card. He needs to use ATM's that have a PLUS logo on them.