Info: Intermittent Connection on Xiaomi / RedMi Phone (SIM Card Shows No Service / No Data)

Intermittent Connection on Xiaomi / RedMi Phone (SIM Card Shows No Service / No Data)

Target Phone:

• Xiaomi Redmi Note 13 5G (OS: HyperOS 2.0.209.0, Android 15)

Symptoms:

• Phone SIM card suddenly not detected, no service / connection
• It happened only on SIM card Slot #1, no issue on SIM card Slot #2

Step 1: Quick Fixes (Simple Check)

• Restart Phone: A simple restart often fixes temporary glitches.
• Airplane Mode: Turn Airplane Mode on, wait a few seconds, then turn it off to refresh network connection.
• Check Mobile Data Setting: Go to Settings > Mobile networks > Mobile data and ensure its toggled ON.
• Preferred Network Type: In the same menu, select Prefer LTE/5G (or 4G/5G) as the preferred network type. 

Step 2: Hardware & SIM Checks

• Reinsert SIM: Power off, eject the SIM tray, check the SIM for dirt/damage, clean it gently with a dry cloth, and reinsert it properly.
• Test SIM in Another Phone: Insert your SIM into another phone; if it still has no data, the SIM card is likely faulty.
• Inspect SIM Slot: Look for dust or debris in the phone's SIM slot. 

Step 3: Advanced Troubleshooting

• Reset Network Settings: Go to Settings > More connectivity options > Data usage > Reset Wi-Fi, mobile networks, and Bluetooth. This reset saved Wi-Fi, mobile data, and Bluetooth settings without erasing personal data.
• Check for Updates: Ensure your phone's operating system is up-to-date (Settings > About phone > System update).
• Developer Options: Go to Settings > About phones > OS version, continuous clicking on "OS version" to activate the Developer mode. Then, go to Settings > Additional Settings > Developer options to set “Mobile Data Always Active”
• Enter Secret Code: Dial *#*#64663#*#* to enter Factory Diagnostic Tool and proceed hardware test to check whether the SIM Cards are working or not. 

Step 4: Ultimate Weapon (Worst Case)

• Factory Reset: As a last resort, back up data and perform a factory reset (Settings > About phone > Factory reset). 
• Get Help from 3rd Party: If these steps do not resolve the issue, it may be necessary to contact your service provider (carrier) for SIM card replacement or visit a professional repair service for further assistance.

My Final Solution:

• Debug done using Step 1, Step 2, and even Step 3, but not solving the issue.
• Suddenly I thought of eject the SIM card tray and bending it slightly, then re-insert it into the phone. This simple step indeed solved my issue. The intermittent connection is no longer happened. It is now having stable mobile data connection.

Xiaomi Secret Code Listing