International Roaming Sim Card

was activated in the Philippines and the load has been smart about it, I'm in San Francisco now and it has no signal

Well, sometimes you need to have your roaming enabled. Its one thing at once. 2, the frequency in the United States is different. Most new phones are so tri or quad-band, but phones are not dual band and does not work in the United States. If this is the case, then you need a phone that will work in the> USA

I think you need a 3G phone for a reception in America.