Expert: DebiN - 10/10/2009

Question
QUESTION: I have attempted to purchase an unlocked cell phone with a quad band for replacement of my current phone (broken), that I use with a Cellular One sim card.  I have purchased a phone from 2 different seller's on Ebay and have had problems.  Both were supposed to be unlocked.  AT&T wants me to upgrade, but I will have to pay $20 more per mo. for less minutes than I have now.  I don't know if the problem I am having is with defective phones or the compatibility with my Cellular One sim card.  Should my sim card be compatible with any gsm phone?  The phone was a Motorola v3xx quad band.

ANSWER: When you say that you have had problems, can you tell me in more detail what problems you have had? Can you make and receive a call? Is the problem regarding accessing the internet or sending and receiving MMS messages? Your SIM card is compatible with any SIM unlocked quad band GSM phone and if the phone works properly, you should be able to put your SIM into it and make and receive phone calls and text messages. Let me know and I am happy to try to help. Thanks. DebiN

---------- FOLLOW-UP ----------

QUESTION: The problems that I encountered were, the first phone was locked, AT&T attempted to help me unlock it and it was not successful, the second phone could receive calls but I couldn't send them.  The replacement for the phone sent back, after placing my sim card in, would recognize my  text messages and messages for voice mail, but it said "no service". It simply was not working.  A rep for AT&T told me that the Cell One sim was not compatible with the Motorola V3xx. I thought any sim that worked with my network would work with any unlocked gsm 850/1900 phone. (the phone I have now is a triband) and works fine. The Seller's both confirmed that the phone should work with my sim.

ANSWER: Thanks so much for the update.

---------- FOLLOW-UP ----------

QUESTION: My final question to the prior stream of events in purchasing an unlocked phone would be, is it possible that the luck that I've had with purchasing these phones is just a fluke?  Or could it be that my Cell One gsm sim card just is not compatible with the Motorola V3xx phone, even though the phone was sold to work on the AT&T network and my current phone works fine with AT&T. How can I find out what kind of unlocked phone would work with my Cell One sim, or just throw in the towel?  Thanks.

Answer
It was not a fluke. That I can be sure of. There are two US bands (850 and 1900). When a phone is tri-band and was made for the US carriers, then the third band is one of the non-US bands (if the phone was designed for non-US then the third band is one of the US bands and consequently won't work properly on AT&T's network since you need both US bands). Your CellOne SIM should work in all SIM unlocked GSM phones that work with both the 850 and 1900 bands. If you want to get a phone, check it's specifications and as long as it works on both 850 and 1900 (non-HSPDA) GSM bands, you should be fine. I hope this helps. Thanks. DebiN