Mobicel X4 Firmware Flash File Download [Stock Rom]

The Mobicel X4 is an affordable Android Go Edition phone built with a Spreadtrum SC7731E quad-core CPU, 1GB RAM, 8GB storage, and a compact 5.45″ display. Like most ultra-budget SPD devices, it can develop severe lag, freezing, random reboots, persistent “stuck at Mobicel logo” bootloops, app crash errors, power drain, dropped Wi-Fi, and camera bugs. When these issues persist after basic resets and maintenance, a full flash using the factory PAC firmware is the most effective fix.

All Mobicel X4 PAC firmware must be flashed only via SPD Upgrade Tool (also known as Spreadtrum/Unisoc Download Tool) on a Windows PC.

Mobicel X4 Firmware Details

Reference hardware/spec list to match device before flashing:

Download Official Firmware for Mobicel X4

• Build: 300520_SPD
  • File Name: Mobicel_X4_300520_8.1.0_SPD.zip
  • Size: 700MB
  • 🔗 Download Link: Download (MediaFire)

Why Flash This Specific Firmware?

• Bootloop and Startup Recovery: Phone stuck at logo, infinite restart—PAC flash updates/restores all critical partitions to original factory state.
• Repair App Crash, Persistent Freezing, and Lag: Wipes out buggy/corrupted apps, malware, rogue configs, and fixes lingering errors causing crash/freeze.
• Fix Camera, Battery, and Wireless Issues: Usually resolves camera errors, Wi-Fi/Bluetooth dropping, battery management bugs unless hardware is damaged.
• Unbrick or Recover Unresponsive X4: Full PAC flash via SPD Upgrade Tool often revives devices that can boot to flashing mode, unless there’s board/memory failure.

Crucial Prerequisites Before Flashing

Make a backup first—flashing will erase everything.

• SPD Upgrade Tool for PAC firmware (Windows PC only).
• Spreadtrum/Unisoc USB drivers for phone connection.

How to Flash the Firmware

1. Download and extract Mobicel_X4_300520_8.1.0_SPD.zip.
2. Install all required Spreadtrum/Unisoc USB drivers on your PC.
3. Open SPD Upgrade Tool (UpgradeDownload.exe).
4. Click the gear icon, select the .pac file from the extracted ROM folder.
5. Power off phone (remove battery if possible).
6. Hold Volume Down and connect device via USB.
7. Click “Start Downloading” and wait for green “Passed” message.

Visual help/FAQ: How to Use the SPD Upgrade Tool

Disclaimer: Firmware flashing erases all user data and may brick device if interrupted or mismatched. Proceed at your own risk.