Wrong frequency? Phone not working overseas

[cimhal]

I got HTC One X on At&T. Went to the store, didn't tell them I was leaving, I had some problem with receiving calls, they changed my SIM and changed the frequency(have no idea to which one from which.) Called them got the unlock code, went to Europe - Poland. Bought a new starter pay as you go card on Play network and next to the bars on top it shows an X and can't make calls or send texts or access the internet except I can use WIFI. I need to mention that AT&T SIM card does the same thing - not responding.
I think it is because AT&T changed the frequency. My wife has a VIVID(locked) and she can send texts, call, etc.
How do I make my phone to work? How to check the frequency I am using?
HELP PLEASE!

 

[Greg C]

I got HTC One X on At&T. Went to the store, didn't tell them I was leaving, I had some problem with receiving calls, they changed my SIM and changed the frequency(have no idea to which one from which.) Called them got the unlock code, went to Europe - Poland. Bought a new starter pay as you go card on Play network and next to the bars on top it shows an X and can't make calls or send texts or access the internet except I can use WIFI. I need to mention that AT&T SIM card does the same thing - not responding.
I think it is because AT&T changed the frequency. My wife has a VIVID(locked) and she can send texts, call, etc.
How do I make my phone to work? How to check the frequency I am using?
HELP PLEASE!

Locked or unlocked only matters if you want to use a sim from the country you're visiting. Your wife's phone may be an international phone meaning it picks up US as well as frequencies used in other countries. It seems you have a US version only HTC One X. There is an international version of the HTC One X. Perhaps you should have asked the AT&T Store rep about this. Even though a phone is GSM doesn't automatically make it an international phone... it has to have the ability to pick up foreign frequencies.

 

[cimhal]

Okay so I called AT&T and they said that their phones are international phones. Only Verizon has US version only phones.
They couldn't help me out and I still have problem with that I have an X next to bars and that the bars are grayed out.
Anyone has an idea for a fix?
When I tap on settings. Airplane mode, WiFi and Bluetooth is OFF. Mobile Network is ON but underneath it says "Disconnected because service is unavailable" When I tap on Mobile network Data Roaming is unchecked.
I tap on network operators and everything is grayed out so I cannot even select networks manually.

 

[Bizzle69]

Top my knowledge the only way you can use it in another country is if you put a different SIM in, from a carrier in that country... Or, you could go into settings-mobile connection-apns and change or add an apn that works

 

[cimhal]

It doesn't work either way.
1. I just powered my phone on when I landed in Europe and had the X next to the bars with AT&T SIM inside.
2. I put in a SIM card from the country I am inand still nothing. I did what Bizzle69 said to change APN. Went and found these but still X next to the bars.
It gets me thinking that the phone is busted

 

[IAmSixNine]

Help us out by telling us what country and carrier your trying to use. From there we should be able to find out what frequency spectrum that country is using for that carrier.
With that info we can then tell you if the device is compatible or not. If your able to put another sim card in it and it doesnt pop up asking you for a Sim unlock code then the phone has been unlocked and thats good.
Also is your One X up to date? Its an ATT branded device but in the early days of release the initial software was not the best when it came to making network connections. The latest is 4.1.1 (going by memory) This is what the device will pick up frequency wise with its current hardware for the ATT version.
2G Network GSM 850 / 900 / 1800 / 1900
3G Network HSDPA 850 / 900 / 1900 / 2100

 

[olynzen]

Hello, I'm just wondering if you sorted this out in the end? I've just experienced the same issue whilst in the UK (the phone was bought in Germany, simlock free on O2 provider), though I've used the phone with no problems in the Netherlands. I thought it might be an issue with Airplane Mode (i.e. phone not coming out of the mode correctly), as this had been the first time I had used this. Since returning to Germany though, my phone is working fine again. Any tips to avoid the problem whilst travelling in the future would be gratefully received!!