logo elektroda
logo elektroda
X
logo elektroda
Advanced Search
logo elektroda

Samsung Galaxy J3 (2016) - "Connection problem or incorrect MMI code

AvatarGT 5865 15
ADVERTISEMENT
Treść została przetłumaczona polish » english Zobacz oryginalną wersję tematu
Report a violation of the law
Reply | New topic
  • #1 16969192
    AvatarGT
    Level 7  
    Posts: 42
    Rate: 5
    Hello! I bought a used Samsung Galaxy J3 (2016). Well, I can not top up my account because after entering the code I get the message: "Connection problem or incorrect MMI code". Amazingly, if I want to check my account status, everything works. I tried to transfer the card to another phone and top up, and of course it topped up. Anyone have any idea what's wrong ??
  • ADVERTISEMENT
  • #2 16969247
    KRY5PIN
    Level 37  
    Posts: 3010
    Help: 312
    Rate: 463
    And another card in this J3 works normally ??
  • #3 16969265
    AvatarGT
    Level 7  
    Posts: 42
    Rate: 5
    Unfortunately not. The same error appears.
  • #4 16969274
    KRY5PIN
    Level 37  
    Posts: 3010
    Help: 312
    Rate: 463
    So you bought a broken phone. What does the seller say?
  • ADVERTISEMENT
  • #5 16969284
    AvatarGT
    Level 7  
    Posts: 42
    Rate: 5
    The seller swore everything was working, he said that the phone was new. Because it actually looked like new. With a box and other things inside.
  • #6 16969382
    tino2003
    Admin of GSM Group  
    Posts: 23677
    Help: 1971
    Rate: 2077
    Restore the factory settings.
  • #7 16969493
    AvatarGT
    Level 7  
    Posts: 42
    Rate: 5
    Unfortunately it didn't help.
  • #8 16970124
    tino2003
    Admin of GSM Group  
    Posts: 23677
    Help: 1971
    Rate: 2077
    Normally internet, connections work?
  • #9 16972807
    AvatarGT
    Level 7  
    Posts: 42
    Rate: 5
    Yes. Everything works as it should.
  • #10 16973267
    rafallos5
    Level 12  
    Posts: 55
    Help: 4
    Rate: 22
    Hey, I noticed this problem in my S6 edge and S7 edge phones after removing frp by combination file. Appears after uploading one of the softches that I have in my database. The problem is solved by uploading another software.
  • ADVERTISEMENT
  • #11 16973448
    tino2003
    Admin of GSM Group  
    Posts: 23677
    Help: 1971
    Rate: 2077
    Since such anomaly colleague noticed it actually uploaded the factory highest available soft odin and should help.
  • ADVERTISEMENT
  • #12 16973472
    AvatarGT
    Level 7  
    Posts: 42
    Rate: 5
    Yes, I will do it and let you know if it helped


    @Edit

    Where is the best to download ROM? Because I uploaded one but nothing has changed, nothing has even been reset.
  • #13 16974448
    rafallos5
    Level 12  
    Posts: 55
    Help: 4
    Rate: 22
    AvatarGT wrote:
    Yes, I will do it and let you know if it helped


    @Edit

    Where is the best to download ROM? Because I uploaded one but nothing has changed, nothing has even been reset.

    The Samfirm program will download the latest available ROM. Alternatively, search on Sammobile, there is a larger selection.
  • #14 16974937
    AvatarGT
    Level 7  
    Posts: 42
    Rate: 5
    Unfortunately, Samfirm did not help me, the rom I downloaded using this program cut my phone. Fortunately, I was able to save him. On Sammobile at the moment you can not download, and even if you can, I do not know if I will want to download at 15kbps.
  • #15 16976076
    beo
    Level 37  
    Posts: 3456
    Help: 298
    Rate: 235
    Did you provide the correct model? F / Fn? There is no option for SamFirm to download a bad rom. Several times I downloaded the rom for the F model and not once, I had no trouble - I skip the fact of the release itself, where, e.g. in July, it affected the phone very badly - I got some of these roms :D
  • #16 16976948
    AvatarGT
    Level 7  
    Posts: 42
    Rate: 5
    beo wrote:
    Did you provide the correct model? F / Fn? There is no option for SamFirm to download a bad rom. Several times I downloaded the rom for the F model and not once, I had no trouble - I skip the fact of the release itself, where, e.g. in July, it affected the phone very badly - I got some of these roms :D


    Yes of course, I downloaded three times and it ended the same way each time. In Odin at "recovery.img" she broke me with Fail and the phone is dead.
Reply | New topic
Report a violation of the law

Topic summary

✨ The user is experiencing a "Connection problem or incorrect MMI code" error when attempting to top up their account on a Samsung Galaxy J3 (2016). They confirmed that the SIM card works in another phone, indicating the issue lies with the device. Suggestions from other users include restoring factory settings, which did not resolve the issue. Some users noted similar problems with other Samsung models (S6 Edge, S7 Edge) after software modifications, recommending the installation of the latest firmware via Odin. The user attempted to download ROMs using the Samfirm program and Sammobile, but faced difficulties, including a failed installation that rendered the phone inoperable. The discussion highlights the importance of ensuring the correct model is selected when downloading firmware.
Generated by the language model.

FAQ

TL;DR: One proven fix is to flash the latest correct stock ROM with Odin. “The problem is solved by uploading another software.” [Elektroda, rafallos5, post #16973267]

Why it matters: This FAQ helps Galaxy J3 (2016) owners who see “Connection problem or incorrect MMI code” when topping up via USSD and want safe, practical fixes.

Quick Facts

What does “Connection problem or incorrect MMI code” mean?

It indicates a USSD/MMI session failed between your phone and the carrier. USSD codes (like *123#) use a real‑time connection for tasks such as balance checks or top‑ups. When this link breaks or the phone interprets the code incorrectly, you see that error. [Unstructured Supplementary Service Data]

Why can I check balance but can’t top up on my Galaxy J3 (2016)?

In the reported case, balance inquiries worked but top‑ups failed on the same device and SIM. That points away from network or SIM faults and toward a phone‑side software issue affecting certain USSD transactions. [Elektroda, AvatarGT, post #16969192]

Will a factory reset fix this MMI error?

Not always. A full reset did not help in the thread case. If the firmware or CSC is mismatched or altered, only flashing the correct stock software typically clears the issue. [Elektroda, AvatarGT, post #16969493]

Does swapping SIM cards help diagnose the problem?

Yes. Another SIM in the same J3 still showed the same error, suggesting the phone software, not the SIM, was at fault. Try another handset with your SIM to confirm. [Elektroda, AvatarGT, post #16969265]

Is this hardware or software?

Evidence points to software. One expert noted the error appeared after FRP removal using a combination file and was resolved by flashing different firmware. “The problem is solved by uploading another software.” [Elektroda, rafallos5, post #16973267]

How do I fix it by flashing stock ROM with Odin?

Three‑step How‑To:
  1. Download the latest factory firmware matching your exact J3 (2016) model.
  2. Flash it with Odin as full stock (AP/BL/CP/CSC), not a combo file.
  3. Reboot, then test USSD top‑up. This approach was recommended by experienced members. [Elektroda, tino2003, post #16973448]

Where should I download the ROM for the J3 (2016)?

Use SamFirm to fetch the latest official package, or browse Sammobile for a wider selection. Ensure the region/CSC and model match your device. [Elektroda, rafallos5, post #16974448]

What if SamFirm flash fails or Odin stops at recovery.img?

That can happen with a mismatched or problematic package. One user reported three failed attempts ending at recovery.img and a temporary soft‑brick before recovery. Re‑verify model/CSC and use a different correct firmware build. [Elektroda, AvatarGT, post #16976948]

How do I confirm J3 model variant (J320F vs J320FN) before flashing?

Check the model ID in Settings > About phone or in Download Mode. Flashing the wrong variant’s ROM risks failure or boot issues. An experienced user emphasized choosing F vs FN correctly. [Elektroda, beo, post #16976076]

My internet and calls work. Is the issue limited to USSD?

Yes, that pattern matches the thread case. Data and voice were fine, while only USSD top‑up failed. This further implicates firmware or CSC handling of MMI/USSD, not radio hardware. [Elektroda, AvatarGT, post #16972807]

What is FRP (Factory Reset Protection), and why is it mentioned here?

FRP is an Android security feature that requires a linked Google account after certain resets. Devices modified for FRP removal using “combination files” can show atypical software behavior, like USSD errors, until proper stock firmware is restored. [Hexnode Help Center]

Is there a quick workaround so I can add credit today?

Yes. Move your SIM to another phone to perform the top‑up, then return it to the J3. This worked reliably for the affected user while the J3 issue persisted. [Elektroda, AvatarGT, post #16969192]

What if flashing the latest stock ROM doesn’t help?

Try a different official firmware build for your exact model/CSC. An expert observed the issue with one build and resolved it by switching software. Quote: “The problem is solved by uploading another software.” [Elektroda, rafallos5, post #16973267]

Could a “new‑looking” used phone still have prior service modifications?

Yes. Even boxed devices can carry prior service changes. In this thread, the seller said the phone was new, yet FRP‑related history and firmware anomalies were suspected. Treat such symptoms as signs to restore clean stock firmware. [Elektroda, AvatarGT, post #16969284]
Generated by the language model.
ADVERTISEMENT