No.1. You might have to search for an ATM that accepts your card
We'd not had any problems getting money out of the ATM in any country in South America. Then we got to Brazil.
After crossing the border, we headed, with our bags to the nearest cash point. It wouldn't accept either my or James' card. Neither would the next two that we came across.
After traipsing around town in the heat with our backpacks, we finally found one that would take my card and got our hands on some dosh.