topic Connection Problem or Invalid mmi code in Z Series

Connection Problem or Invalid mmi code

kenneth2222 — Fri, 15 Aug 2014 12:50:31 GMT

No problem with signal and wifi. I cant make and recieve calls, even text message not allowed, and when I dialled *121# connection Problem or Invalid mmi code comes out. Please help me what to do. I have reset my phone to factory settings but nothing happened

Re: Connection Problem or Invalid mmi code

JiYong — Fri, 15 Aug 2014 14:33:08 GMT

Can you tell us which provider you are on and in which country?

The MMI code *121# what is it supposed to do?

Can you disable Wifi and post a screenshot of your home screen?

I'm mostly interested in the top bar, so you can cut off the rest when your home screen reveals privacy information.

Re: Connection Problem or Invalid mmi code

Alexander1 — Fri, 15 Aug 2014 14:38:56 GMT

Mmi code is an error message from the network. I suggest that you raise this with your network provider to see if they can see what's wrong. You could also try with another SIM card in your phone.

Re: Connection Problem or Invalid mmi code

kenneth2222 — Sat, 16 Aug 2014 16:41:05 GMT

I tried another sim card and it worked, im from Philippines btw. My problem now is the phone is openline to any network why it only worked in one network provider only. and I need to use my previous sim card. Here in Philippines our network provider names are Sun, Smart and Globe. The only network provider working in my phone is Sun, I need to use my Smart sim card. My Smart and Globe sim cards are now useless because It cannot make or recieved calls and text plus the connection problem and invalid mmi code problem too.

Re: Connection Problem or Invalid mmi code

JiYong — Mon, 18 Aug 2014 17:30:39 GMT

Where did you buy this phone?

It looks like the phone is still locked to one service provider.

Again, what is the MMI code *121# supposed to do?

Re: Connection Problem or Invalid mmi code

rolle_f — Thu, 21 Aug 2014 06:42:50 GMT

I had the exact same problem but I live in sweden. My solution was to send the phone for service and I got a new one.

It could be something wrong with the SIM-card reader.

Re: Connection Problem or Invalid mmi code

lloydchronus — Thu, 24 Sep 2015 08:29:58 GMT

Same problem have you fix yours ?

Re: Connection Problem or Invalid mmi code

M425 — Fri, 18 Aug 2017 17:03:06 GMT

I have a Sony m4 aqua.last some days I saw that my phone have a mmi code problem .when I found this problem I reset my phone.but still I found mmi code wrong in my phone.how can solve this type of problem ? I live in Bangladesh.

Re: Connection Problem or Invalid mmi code

Loverly24 — Wed, 07 Feb 2018 20:04:24 GMT

How to set my experia z4 from 3G to 4G?

Re: Connection Problem or Invalid mmi code

Uliwooly — Wed, 07 Feb 2018 21:49:56 GMT

@Loverly24

Do you have an Xperia Z4 Tablet? or a Z3+ ?