I bought this calculator in August in the US and brought it to Uruguay. Some buttons stoped working so I sent it to the HP service here in Uruguay. They told me that the motherboard is broken and that they can't fix it. I'm trying to register my calculator but the support page doesn't recognize the serial number. In the service they told me to get in contact with HP in the U.S. so that they replace it, and this is the only way I can do that.