Cellular data is a basic phone feature today but after Installing a custom ROM, you may loose this function. If 4G/5G has stopped working after installing a custom ROM and you still want to use those networks then you must refer to this article because it has all the latest and proven methods of solving them. This tutorial contains all the solutions to your cellular network problem, no matter whether you have Pixel Experience, LineageOS, crDroid, or any AOSP-based ROM.
✅ The most typical reasons behind 4G/5G not working on custom ROMs
- Modem firmware that is incompatible or old
- Wrong APN (Access Point Name) settings
- Different region firmware
- The choice of the network mode is incorrect
- Network or radio configs are damaged
- The incomplete installation of the ROM or missing files for the vendor.
We’re now going to dive into each fix one by one.
🔁 Fix 1: Clear and Remake APN Settings
Most likely, your cellular data has been blocked by incorrect APN values. The quickest and safest solution is to reset and enter them again.
Steps:
- Select Settings > Network & Internet > Mobile Network > Access Point Names.
- Pick your SIM slot (active one).
- Tap the current APN and then make a screenshot of all of the fields.
- Click menu (⋮) and select Reset to default option.
- Power off your device and then turn it on again.
- If the APN is not done automatically, copy it from your screenshot and type it in manually.
📌 Extra Hint: Get the newest APN from your carrier’s official website.
🌐 Fix 2: Flash the Correct Regional Firmware for Modem Compatibility
A cross-region firmware that is not specially made for your carrier may contain modem configurations that are incompatible with your carrier.
Solution:
- Find out the region of your device (for example IN, EU, US) using fastboot getvar all or the original stock build.
- Get a proper firmware package directly from the website of the manufacturer (e.g., Xiaomi, Samsung, OnePlus).
- Upload only the modem (baseband) partitions like NON-HLOS.bin, modem.img, or you can also use fastboot by executing the following:
fastboot flash modem NON-HLOS.bin
- Turn on and check mobile data once you have finished flashing.
☎️ Fix 3: Use ##4636## to Force Network Mode
Most likely, a manual selection of the correct radio mode will clear the incompatibility issue of a custom ROM.
Procedure:
- Make a call by entering *#*#4636#*#* on your device.
- Head over to Phone Information > Set Preferred Network Type.
- Pick anyone of the option given below according to your service provider: NR/LTE/WCDMANR/LTELTE/WCDMANR Only (for 5G-exclusive SIMs)
- NR/LTE/WCDMA
- NR/LTE
- LTE/WCDMA
- NR Only (for 5G-exclusive SIMs)
- Restart your device.
🛑 Warning: Be sure not to select a combination such as CDMA/EvDo, which is unknown, and your carrier is not using.
🔄 Fix 4: Perform a Complete Network Reset
Old and obsolete network settings are like dirty flashes that eventually cause data services to malfunction. We mean to say increasing chances of Cellular data issue after custom ROM.
Steps to Format Network Settings:
- Settings > System > Reset Options > Reset Wi-Fi, Mobile & Bluetooth is where you should go.
- When prompted, confirm the reset.
- Restart your phone.
- If data is not switched on automatically, reinsert SIM.
🧰 Fix 5: Flash Full Firmware + Vendor via Fastboot (For Pixel/AOSP ROMs)
Certain Custom ROMs are just void of firmware and vendor files, which are undeniably needed for compatibility with radio.
For Pixel Phones or Generic Devices:
- Get the complete factory image of your device’s latest stock firmware.
- Unpack only vendor.img, modem.img, and the rest of the radio or firmware images.
- Flash each with the following command:
fastboot flash vendor vendor.img
fastboot flash modem modem.img
- Reflash the new ROM but make sure it is a clean wipe.
📞 Fix 6: Contact the ROM Developer for Known Bugs
When everything else seems to be a failure, the source of the trouble is still the ROM or the incorrect implementation of HAL.
Steps to Report:
- Go to the legitimate thread (XDA, GitHub, or Telegram).
- Send your device log through ADB:
adb logcat -b radio -d > radio_log.txt
- Define your carrier, baseband version, and the correct ROM build in the report you are sending.
🛠️ Several developers get ready their fixes timely after listening to the problems.
🔎 Optional: Use QPST/QXDM to Diagnose Radio Issues (Advanced)
The utilization of the QPST or QXDM instruments for the Qualcomm gadgets plans will be their deep-going diagnostic insight in detail.to LTE and 5G status.
📌 Final Notes & Best Practices
- When changing the base of a ROM, always use a clean flash.
- Before you flash anything, backup the essential partitions with TWRP.
- Stay away from flashing the ROMs that are designed for the other device variants or different regions.
- Always have your carrier’s APN profile saved offline.
Employing these methods over 95% of 4G/5G issues occurring in custom ROMs can be fixed without changing the kernel or going back to the stock ROM. However, if the problem is still there after trying all these solutions, it could be a hardware issue or a bug in the ROM’s source code that has not been fixed yet. If you found any other way to fix Cellular data issue then simply comment down below as the more details you provide about the ROM and the device, the quicker you will get help.