This page provides the official download links for the Celkon Diamond U 4G stock ROM for all its hardware variants. The Diamond U 4G was a budget smartphone released with different RAM and storage configurations. It is critically important that you download and flash the correct firmware that matches your phone’s specific hardware (e.g., 1GB/8GB, 2GB/16GB). Flashing the wrong version will likely cause your device to bootloop or become bricked.
This firmware package, which contains the original Android 7.0 Nougat OS in a .pac file, is the ultimate solution for fixing major software issues. Use it to unbrick a Celkon Diamond U 4G, remove persistent malware, or recover from a failed update. The installation is performed with the SPD Upgrade Tool for its Spreadtrum chipset.
User Data and Security Advisory for the Diamond U 4G – Issued: 4:25 AM, Wednesday, September 17, 2025
Critical Local Warning: This flashing process will permanently erase all your personal data. A backup is essential. Flashing the incorrect firmware for your specific RAM/Storage variant can brick your phone. Please choose carefully. Android 7.0 is no longer supported with security updates, making it vulnerable to online threats. This process is recommended for restoration purposes only.
Celkon Diamond U 4G: Quick Device Specifications
The Celkon Diamond U 4G was released in multiple hardware versions. Confirm your device’s RAM and Storage before downloading.
- Device Model:
- Celkon Diamond U 4G
- Release Date:
- 2017
- Chipset:
- Spreadtrum SC9832 (Quad-core 1.3 GHz)
- Display:
- 5.0 inches, 720 x 1280 pixels (HD)
- Battery:
- 2500 mAh
- RAM/Storage Variants:
- 1GB/8GB, 1GB/16GB, and 2GB/16GB
- Key Features:
- 4G VoLTE Support
Required Downloads for Flashing
You will need the following specific tools and drivers for Spreadtrum devices.
- SPD Upgrade Tool
- Spreadtrum USB Drivers
- The Correct Celkon Diamond U 4G Firmware Package (from the table below)
Celkon Diamond U 4G Firmware Download Links
| Hardware Variant | Filename / Version (Build Date) | Android Version | Size | Download Link/s |
|---|---|---|---|---|
| 2GB RAM / 16GB Storage | Celkon_U_2_16_V06 (Apr 2017) | 7.0 Nougat | 1.1GB | Download (MediaFire) |
| 1GB RAM / 16GB Storage | Celkon_Diamond_U_1_16_V12 (Feb 2017) | 7.0 Nougat | 1.1GB | Download (MediaFire) |
| 1GB RAM / 8GB Storage | Celkon_Diamond_U_1_8_V10 (Feb 2017) | 7.0 Nougat | 1.1GB | Download (MediaFire) |
How to Flash Celkon Diamond U 4G Firmware (.pac file)
This is a summary of the flashing process using SPD Upgrade Tool. For a more comprehensive guide with screenshots, please visit our detailed pillar article.
- Preparation: Download the correct firmware for your variant, the SPD Upgrade Tool, and Spreadtrum drivers. Extract all zip files into a single folder.
- Driver Installation: Install the Spreadtrum USB drivers on your computer and restart if prompted.
- Load Firmware: Run
UpgradeDownload.exe. Click the first Gear icon (“Load Packet”) and select the.pacfirmware file you extracted. - Start Flashing: Click the Play button (“Start Downloading”) to put the tool into flashing mode.
- Connect the Phone: Power off your Celkon Diamond U 4G completely. Press and hold the Volume Down key. While holding the key, connect the phone to your PC via a USB cable.
- Completion: The tool should detect the phone and begin flashing. You can release the volume key once the progress bar appears. A green “Passed” message will indicate the process is complete. Disconnect the phone and power it on.
For in-depth instructions and troubleshooting for the SPD Upgrade Tool, please visit our complete guide: How to Use the SPD Upgrade Tool to Flash Your Smartphone.
Troubleshooting Common Issues
Here are some specific issues you might encounter with the Celkon Diamond U 4G.
1. Phone is Bricked or Stuck in a Bootloop After Flashing
Cause: This is the most common symptom of flashing the wrong firmware variant. For example, flashing the “1_8” (1GB/8GB) firmware on a “2_16” (2GB/16GB) device will almost certainly cause a bootloop or a dead phone because the partition sizes and hardware drivers are incorrect.
Solution: Double-check the RAM and storage capacity of your physical device (it may be written on the box or on a sticker under the battery). Download the correct .pac file from the table above that matches your hardware and re-flash it using the same procedure.
2. 4G VoLTE Not Working or No Network
Cause: A failed update or software corruption can damage the modem configuration files, leading to an inability to connect to the 4G network or make VoLTE calls.
Solution: A full flash with the correct stock .pac file will restore the original, working radio and modem firmware, which can fix software-based connectivity problems.
3. SPD Upgrade Tool Fails With an Error
Cause: Errors during the flashing process are typically related to drivers. The tool cannot establish proper communication with the phone’s chipset.
Solution: Reinstall the Spreadtrum drivers and restart your PC. Use a different USB port and a high-quality USB cable. Make sure to press and hold the correct boot key (usually Volume Down) *before* plugging in the cable to force the phone into download mode.
Frequently Asked Questions (FAQs)
- How do I know which firmware to download for my phone?
- You must know your phone’s RAM and Storage configuration. The filenames clearly indicate this: “2_16” is for the 2GB RAM/16GB Storage model, “1_8” is for the 1GB RAM/8GB Storage model, and “1_16” is for the 1GB RAM/16GB model. You must flash the file that matches your specific device.
- What happens if I flash the wrong firmware version?
- Flashing firmware for a different hardware variant is very risky. It will likely cause the phone to get stuck in a bootloop, or it may not turn on at all (a “soft brick”). To fix this, you must flash the correct firmware file for your device.
- Will this firmware remove the FRP (Google Account) lock?
- Yes, in most cases. A full flash using the SPD Upgrade Tool overwrites all device partitions, including the one that stores the FRP lock. This is a common and effective method for bypassing FRP on Spreadtrum devices.
- Why is my phone’s performance slow?
- The Celkon Diamond U 4G is a budget device. Even the 2GB RAM model has an entry-level processor. A clean firmware flash will restore its best possible performance, but it will still struggle with demanding, modern apps.
Conclusion
Restoring the official stock firmware on your Celkon Diamond U 4G is the most effective way to solve major software issues. However, it is absolutely essential to choose the correct firmware file that matches your phone’s specific RAM and storage configuration. This guide provides all the official variants and a reliable flashing method to get your device back into working order. Double-check your hardware, back up your data, and proceed with caution.
If this guide helped you, please share your experience in the comments, especially which firmware version you used. Your feedback helps our community!
