UNLOCKED Samsung B2100 will not recognize Tmobile sim, recognizes AT&T sim

**lambchop27** · 10-27-2010, 05:09 PM

The phone worked with a borrowed, older Tmobile sim, but not with a new one. I tried 2 different, brand new Tmobile sims, neither worked. The phone kept cycling on and off with newer Tmobile sims. I borrowed a friend's older Tmobile sim and the phone works fine. It also works fine with an older AT&T sim, don't have a new AT&T sim to try. The phone is definitely unlocked.
Any suggestions? is there a setting or something that can be adjusted manually?
I don't believe any US carrier ever sold this phone. The phone is likely from the UK, not sure, I got it on Ebay.
You can find specs for this phone here:
http://www.samsung.com/ph/consumer/m...ype=prd_detail

Thanks in advance for any advice!

**lambchop27** · 10-30-2010, 12:05 PM

I've contacted TMobile about their sims. They don't know/won't tell me the tech. differences between old and new sims, they definitely won't talk to me about my phone as I did not buy it from them. I was directed to contact Samsung. I contacted Samsung USA, they told me I had to phone Samsung UK. I phoned Samsung UK and they told me I had to contact Samsung USA. Seems like everyone wants to defer to someone else for trouble shooting. Pretty frustrated.

**Scottish Skyedance** · 11-01-2010, 01:01 AM

Wirelessly posted (HTC Nexus One: Opera/9.80 (Linux armv7l; Maemo; Opera Mobi/4; U; en) Presto/2.5.28 Version/10.1)

I think the newer version SIM is USIM and some phones may have problem with it.
Solution: get older version SIM from ebay (with Get More from Life motto) and try again. Once the phone can read the SIM, call CS to switch.

**lambchop27** · 11-01-2010, 04:41 AM

Thanks for taking the time to help-
I actually already have an older sim from ebay on it's way here.
Is a usim the same as a uicc sim?
According to TMobile, they use a uicc standard sim and they introduced it about 2 years ago. My phone is only 1 year old.
Any ideas on why this may be happening with my phone?
I'm just wondering in case I'm stuck needing a new sim down the road.
thanks again

**brucekjacobs** · 09-03-2011, 05:19 PM

hey there

I have just come across exactly the same problem. Completely ridiculous. Could you tell me how you sorted it? what is the point of a quad band phone that doesnt work with the sim cards???? any help really appreciated

**lambchop27** · 09-03-2011, 05:36 PM

I'm afraid I could never get the phone to work with a tmobile card. It's gathering dust as we speak. I tried every avenue I could. I even phoned Samsung Korea where it was made. I also phoned Samsung UK and the Samsung tech support here in the US. I bought a few Tmobile sims on Ebay, but none of them worked. TMobile also told me they were stopping the support of the older Tmobile cards. There is no software update for the phone (that I can find). No one at TMobile could tell me exactly how the newer sim cards were different from the "older" sim cards, just that the newer ones "offered better features" or something. The phone was locked to a carrier in the UK when i got it and would not accept either ATT or Tmobile card. I managed to fully unlock it, then it would only accept the ATT card. I believe the phone is fully functioning, just not with the Tmobile card. The weird thing is that on the Tmobile support forum, i just read that someone with the same exact phone is having trouble sending mms messages. He posted it just this past August, nothing about any difficulties with the sim card. If you learn anything, please let me know.

**brucekjacobs** · 09-04-2011, 06:56 AM

thanks so much for the reply - you have saved me a great deal of time! Did you find that the AT&T sims do work on it?

**lambchop27** · 09-04-2011, 08:51 AM

The whole thing was really an exercise in frustration. Everyone I spoke to said that the phone "should" work with Tmobile, then passed me on to someone else. When I tried the ATT sim, I had just switched away from ATT and signed on with Tmobile. So the ATT sim I tried was about 2 years old, so not sure if they have updated their sim too. The reason I know that it worked with an older Tmobile card is that after the Tmobile store couldn't help me get the phone to work, they suggested a cell phone repair shop down the road. It was there that the repair guy put in an older Tmobile sim that he had in a dusty old drawer, and it worked, baffling both of us. That's when we deduced that there must be something in the newer Tmobile sims that is incompatible. The repair shop's rates were too high to justify leaving the phone with them and they wouldn't guarantee that they could figure it out, but they would charge me by the hour. Anyway, if you do decide to go with ATT, make sure you go to an ATT store to double check that one of their sims will work before you sign on with them. Good luck!