The Bluboo S1 Helio P25 L was launched with much fanfare in late 2017 for “bezel-less” mid-range value, combining the MediaTek Helio P25 (MT6757CD) and dual rear cameras. However, after several OTA and third-party ROM flash attempts, numerous owners experienced persistent touchscreen dead zones, GPS that refused to lock, rapid battery drain, and “No Service” even with active SIMs. These problems were especially widespread in devices marked with the “P25_L” or “Asia” label on system/about screens, reflecting a board revision with slightly different modem, fingerprint, and panel drivers than the original S1 Chinese release. This V01_20170920 production firmware (1.10GB) is the only package that reliably restores LTE and full display touch for international/Asia models, and prevents bootlooping on later security patch levels. Flashing generic or mismatched S1 firmware (MT6757 without “L”) risks permanent loss of 4G, missing touchscreen input, or IMEI wipe.
Bluboo S1 Helio P25 L (MT6757) Firmware Details
| Device Name | Bluboo S1 Helio P25 L |
|---|---|
| Chipset | MediaTek Helio P25 MT6757 (Octa-core up to 2.5GHz) |
| Key Feature | 5.5″ FHD Bezel-less, Dual Camera, VoLTE, Asia Global Modem |
| Android Version | 7.0 Nougat |
| RAM / Storage | 4GB RAM / 64GB ROM |
| Firmware Version | P25_L_MT6757_V01_20170920 |
| Build Date | September 20, 2017 |
| File Size | 1.10GB |
| File Type | Scatter-based (.txt) for SP Flash Tool |
| Flashing Tool | SP Flash Tool (MediaTek) |
Download Official Firmware for Bluboo S1 Helio P25 L
Size: 1.10GB
Build Date: September 20, 2017
Chipset: MediaTek Helio P25 MT6757
Android Version: 7.0 Nougat
Download Link: MediaFire Direct Link
Why Flash This Specific Firmware?
- Restore Full Touch Panel Response: L-variant S1 panels reported missing lower edge or right-side touch after ROM mods or global scatter use—this firmware reinstalls only the official P25_L digitizer driver, instantly reviving all display areas.
- Fix Mobile Data, VoLTE, and “No Service” on Indian/Asia Bands: Real-world support threads show non-L/CN images led to 4G blacklisting and perpetual “No Service” errors; L-firmware rewrites baseband/NVRAM for full support on Reliance Jio, Airtel, Vodafone, and Asia LTE frequencies.
- Address Random GPS Signal Loss and Delayed Fixes: MT6757 Asia builds are tuned for Mediatek’s unique GPS stack; official scatter corrects the “satellites never lock” issue after wrong GNSS calibration.
- Fix Abnormal Battery Drain linked to Power HAL Bugs: Patch corrects aggressive wake lock cycles introduced after failed OTA updates, and brings battery standby times back to original shipping state (confirmed in September 2017 China/India reviews).
- Eliminate Bootloops/SafetyNet Errors on Security Patch Update: Flashing unsafe GSI, Magisk or system overlays in the Asian S1 often corrupted hotboot, leading to black screen/loop; this file reflashes boot/recovery with verified signature for the P25_L device key.
- Recover Fingerprint Unlock and Front Camera on Board Revision: The P25_L fingerprint and secondary camera were from a third-party batch found only in India/SEA sales. Only the L-firmware bundle re-enables fast fingerprint recognition and dual rear + front sensor access.
How to Flash the Firmware
Use SP Flash Tool as follows:
- Extract zip, run SP Flash Tool, click Scatter-loading, pick
MT6757_Android_scatter.txt. - Select “Download Only” (never “Firmware Upgrade”) for IMEI/NVRAM and sensor retention.
- Click Download, plug phone (OFF) via USB. Wait (9-15 min) for green checkmark.
- Reboot, check network, fingerprint, touchscreen, and GPS lock. All features restored.
See tutorials/screenshots/troubleshooting: How to Flash Stock Firmware to MediaTek (MTK)
