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Firmware ZTE Blade A55 firmware Updated 2026-07-23

How to Flash ZTE Blade A55 (Z2450) Stock Firmware (SPD Upgrade Tool) — Fix Bootloop, Unbrick & FRP

If your ZTE Blade A55 is stuck in a bootloop, soft-bricked, FRP-locked or refusing to boot after an update, reflashing the stock firmware is the clean fix. This guide walks the whole process for the ZTE Blade A55. The ZTE Blade A55 runs on the Unisoc SC9863A chipset, so it flashes with the Unisoc SPD Upgrade Tool (ResearchDownload) — the Unisoc/Spreadtrum flashing app for Windows. ROM Palace hosts 4 official stock firmware files for this model as a free, resume-supported direct download.

Before you start

  • Back up anything you can — flashing erases the phone.
  • Charge the battery above 50% so it cannot die mid-flash.
  • Confirm your exact model code (Z2450) in Settings > About phone or on the box — flashing another model’s firmware can brick the device.
  • Use a Windows PC and a good-quality USB data cable (not a charge-only cable).

💡 Flashing the wrong firmware, or pulling the cable during a flash, can hard-brick the phone. Only use the firmware listed for the ZTE Blade A55 on its ROM Palace page.

What you need

  • The ZTE Blade A55 stock firmware — download it free from the ZTE Blade A55 firmware page on ROM Palace.
  • the Unisoc SPD Upgrade Tool (ResearchDownload) — the Unisoc/Spreadtrum flashing app for Windows.
  • the Unisoc / SPD USB driver installed on the PC so the tool can see the phone.

How to flash ZTE Blade A55 stock firmware

  1. Install the SPD/Unisoc USB driver on your PC, then open the SPD Upgrade Tool (ResearchDownload).
  2. Load the firmware: choose Load Packet / Load Firmware and select the .pac file you downloaded.
  3. Press Start Downloading so the tool is armed and waiting for the phone.
  4. Power the phone off completely.
  5. Hold the boot key (usually Volume Down, on some units Volume Up) and connect the USB cable while still holding it — the tool detects the phone and the bar starts.
  6. Wait for PASSED (green). Do not touch the cable until it finishes.
  7. Unplug and power on — the first boot after a flash can take several minutes.

💡 The ZTE Blade A55 uses a Unisoc SC9863A SoC — a chip-type mismatch means you have the wrong .pac or the wrong tool — re-check that the firmware is the one listed for this exact model.

Common problems and fixes

  • Stuck in a bootloop after an update: flash the matching stock firmware from this page to restore a clean system.
  • Tool never detects the phone: reinstall the Unisoc / SPD USB driver, try another USB 2.0 port, and connect with the phone fully off.
  • FRP / Google account lock after a reset: flashing the full stock firmware clears the locked system partition.
  • Battery drains fast or the phone won’t hold a charge after an update: reflash the stock firmware; if it persists, the 5000 mAh cell itself may be worn.
  • Failed or interrupted OTA: a clean stock flash is the safe way back to a bootable system.

ZTE Blade A55 specifications

The specs below are what the ZTE Blade A55 firmware on this site targets:

SpecDetail
ChipsetUnisoc SC9863A
Display6.75" IPS LCD · 90Hz
Battery5000 mAh
CameraMain 13 MP, AF; Front 8 MP
SoftwareAndroid 14
Model codeZ2450

⬇️ Need the software? Download official ZTE Blade A55 stock firmware free on ROM Palace — direct links, no waiting queue.

Frequently asked questions

What tool flashes the ZTE Blade A55?

The ZTE Blade A55 uses the Unisoc SC9863A chipset, so it flashes with the Unisoc SPD Upgrade Tool with the .pac firmware on Windows. Load the firmware, arm the tool, then connect the powered-off phone.

Where can I download ZTE Blade A55 stock firmware for free?

ROM Palace hosts 4 official stock firmware files for the ZTE Blade A55 as a free, direct, resume-supported download — no queue, no quota, no sign-up. Open the model’s firmware page and pick the build for your region.

Will flashing fix a bootloop or FRP lock on the ZTE Blade A55?

Yes. Flashing the matching stock firmware rewrites the system and boot partitions, which clears a bootloop, a corrupt update or an FRP/Google lock left after a factory reset. Always use the firmware listed for your exact model code.

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