1 2 Previous Next 28 Replies Latest reply: Apr 18, 2012 12:07 PM by 21stnow Go to original post RSS
      • 15. Re: My HTC Amaze 4G Unlocking Experience

        This is in reply to both of you, Philyew and Rudie32:


        I don't see what an old (pre-WiFi calling) T-Mo SIM card would accomplish when my problem is with a non-TMo carrier. So far I tried two different AT&T SIM cards, but they both might have been without data plan, if that might mean any difference. My problem is that I don't even get bars with AT&T SIM even though the guy who lent me the card was getting 5 bars on his phone. Now there is the outside chance that the APN I added did not have all its entries correct, so I might research that again.Better yet, I'd appreciate, Rudie32, if you looked up in your phone what those APN entries were and compare them with the ones I posted here earlier.


        After a manual scan, AT&T shows up (but not in the Notification panel), but when I try to select it to register, it gets refused with some error message saying that the SIM card cannot be registered with the network. No wonder if I don't even get any bars, right? That LTE SIM card is a good question and frankly, I don't know if it was an LTE or not. However, I guess it was not, because the guys used older phones and I don't even think AT&T has LTE deployed in the Seattle area yet. I doubt the guys were even on any data plan.

        I wish I could just talk to some knowledgeable guys in a T-Mo store, but they either don't handle this kinds of problem, or are not that knowledgeable beyond selling.


        BTW, are those APNs stored in the phone or in the SIM card?

        • 16. Re: My HTC Amaze 4G Unlocking Experience

          If its telling you sim cannot be registered with the network, it's an at&t issue. You need to call them and ask why they are refusing network access from an at&t sim This doesn't look like an tmobile issue. T-mobile won't block a phone from accessing another network unlocked.

          • 17. Re: My HTC Amaze 4G Unlocking Experience

            Is there an AT&T store near you, or can you call the customer service number (1-800-331-0500, press 0 because you don't have an account with them)?  They may be able to help you out with this.  Since the issue is that you are trying to make sure that the phone works with another service, the other service provider will be more helpful to you than T-Mobile will since you are having no trouble accessing the T-Mobile network.


            I'll warn you now that the hold times may be long on AT&T's Customer Service line.  People are still calling in to get old iPhones unlocked and that has increased wait times over the past several days.

            • 18. Re: My HTC Amaze 4G Unlocking Experience


              Of course, I am glad I was able to respond, even if it was with limited information.

              I have read through all the suggestions and they sound great actually. Trying different ATT SIMs and also ensuring the proper APNs would be the best step. Those would also be the steps we would do if have you called in. 21stnow gives good advice as well. Try a AT&T store to see if they have a different lineup of SIMs. Just like how we now have different generations of SIMs, they may as well. We see instances frequently where newer SIM generations have to be put in newew phones.

              So chech that out. I'd love to hear what happens.


              • 19. Re: My HTC Amaze 4G Unlocking Experience

                I assume you know for a fact that the AT&T SIM registers ok on their network in an AT&T supplied device?


                That rules out it being an inherent problem with the SIM.


                I also assume your phone works fine with its supplied TM SIM.


                My suggestion about using an older TM was to eliminate the possibility that your device is in some way only able to function with the new SIM version that supports wifi calling. I know it's highly unlikely, but it would help to eliminate another variable.


                We know that other Blaze devices work as advertised with an AT&T SIM, so there is no general blocking of unsupported devices on their network.


                Trying a second AT&T card will potentially isolate the problem to the current SIM. If not, then it looks like a device configuration issue.


                I just tried to get an unlocked TM to do anything other than challenge for an unlock code when booted with an overseas SIM. Wouldn't do it, so you do look unlocked right now.

                • 20. Re: My HTC Amaze 4G Unlocking Experience

                  Okay guys, I can finally report some good news. Fortunately, there is an AT&T store right across the street from a nearby T-Mo store, so after reading your suggestions I ventured to try some help there. Actually, I was eventually planning to see them but first I wanted to explore everything I could on the T-Mo side. Anyway, luckily there was a nice and helpful guy in the store who gave me a prepaid AT&T SIM card to try. Interestingly, somehow he also knew that I was on a T-Mo prepaid plan without me telling him. After starting up the Amaze with the AT&T SIM, the situation looked the same as with the previous AT&T SIM cards I tried, but as I was trying to drill down on the Setup menu to the network options, suddenly I noticed 5 bars lighting up like a christmas tree. I could hardly contain myself. Soon I also saw a 2G data indicator on the screen's top bar. The rep then mentioned that I probably should not expect more because of the different data bands used by T-Mo. I mentioned to him that this phone in unlocked state actually has the 850 and 1900 bands AT&T uses and I've heard of other Amaze owners who were able to get 3G or 4G speeds on AT&T network. Apparently he was not aware of this. Then he also suggested to check the network setup menu and set it to GSM-only, instead of "GSM and WCDMA." I didn't like that suggestion because I know that the data uses WCDMA protocol (just another name for UMTS) and only the talk and texting uses GSM. So I set it to "GSM and WCDMA" which immediatly turned on the 4G indicator on the screen. Whoa, now we were getting somewhere! However, when I tried to bring up some web pages, it looked very slow. So I ran the Ookla Speed Test app, and that showed only 2G speed. This made me think that setting the "GSM & WCDMA" option only resulted in the "4G" indicator show up without getting the actual 4G speed. Perhaps the SIM card did not really authorize data use, I don't know, but I am still pretty happy with the results of my visit in that store and will be more confident to take this phone with me to Europe.


                  I still don't understand though why I could not make the prior AT&T SIM cards work for me. Perhaps because they were not prepaid cards like what I use with T-Mo and what I tried at this AT&T store? Who knows ... What do you guys think about this?

                  • 21. Re: My HTC Amaze 4G Unlocking Experience

                    I'm glad that the idea of trying a second SIM worked for you. I can't think of a reason why a valid SIM for a post-paid AT&T account would not work where a pre-pay would. It's not obvious either why you would see a 4G indicator, but only be able to test on their 2G network. If you were seeing a 4G indicator throughout the test, I'd say the poor performance was more to do with an issue with their 4G.

                    • 22. Re: My HTC Amaze 4G Unlocking Experience

                      Not all sims are created equal with at&t. So, anythings possible.

                      • 23. Re: My HTC Amaze 4G Unlocking Experience

                        The network may have been congested when you ran the speed test and loaded the web page.  Network speeds will vary from time to time.


                        I have no idea why a prepaid SIM card would work and a postpaid one wouldn't, unless it was like you said, that the two postpaid SIM cards that you tried didn't have data service on them.

                        • 24. Re: My HTC Amaze 4G Unlocking Experience

                          ...But even then, they should have allowed him access to voice service...

                          • 25. Re: My HTC Amaze 4G Unlocking Experience

                            That's right, I should at minimum get the GSM bands working for voice and texting. I am looking for another chance to borrow somebody else's AT&T SIM card and see what happens then. I suspect though that, as rudie32 noted, there may be some minor variations among different generations of AT&T SIM cards, just as T-Mobile has older and newer ones. Perhaps even iPhones use somewhat different SIMS than the rest of AT&T phones. I seem to recall some articles about Apple wanting to use different SIMs but I don't know if they already do that. In any case, thank you all for helping me through this and I let you know when and if later I discover something else that could shed some light on this anomaly.

                            • 26. Re: My HTC Amaze 4G Unlocking Experience

                              The iPhones 4 and 4S use a microSIM card.  If you tried to use this in your phone without a SIM card adapter, then the SIM card may not have lined up well.  That would cause the lack of connectivity that you mentioned.  If your friends had an iPhone 3GS or earlier, those use regular SIM cards and should not have caused any problems.

                              • 27. Re: My HTC Amaze 4G Unlocking Experience

                                The AT&T SIM cards did not require any adapter and were the same size as my T-Mo SIM card. Couldn't there be some other differences in iPhone SIM cards besides the physical size or shape? Remeber, T-Mo SIM cards for WiFi calling are also different somewhat internally from those without that functionality. iPhone SIM cards may have something different for iTunes access, for instance. I don't know, I'm just saying ...

                                • 28. Re: My HTC Amaze 4G Unlocking Experience

                                  There should not have been anything in the SIM card to prevent you from using it in the Amaze.  Other than the size, there are no other differences between iPhone SIM cards and other SIM cards, due to the phones.


                                  I used my iPhone 4 (with adapter) SIM card in the Vibrant and Nexus S extensively, and only to unlock my Sensation.  I had no problems with the first two phones and didn't use it in the Sensation enough to know.

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