The Positivo S421 is an entry-level smartphone powered by MediaTek MT6737M. Common user complaints include bootlooping and dead boot after failed updates or wrong flash, stuck on logo, touch not working post-flash, persistent FRP (Google) lock, and issues restoring after full format in SP Flash Tool. Using the matching firmware restores bricked/dead S421, fixes touchscreen and boot logo faults, and helps remove FRP lock or system instability.
Positivo S421 MT6737M Firmware Details
| Device Name | Positivo S421 |
| Chipset | MediaTek MT6737M (Quad-core, 1.25GHz, Mali-T720MP2) |
| RAM/Storage | 1GB/8GB (microSD expansion supported) |
| Display | 5.0″ LCD, 854×480 px |
| Camera | 8MP Rear, 2MP Front |
| Battery | 2000mAh removable |
| OS | Android 6.0 Marshmallow / 7.0 (varies) |
| Firmware Filename | Positivo_S421_MT6737M_05012017.zip |
| Firmware Version | 05012017 |
| File Size | 993MB |
| File Type | .zip (contains MTK scatter/SP Flash Tool files) |
| Flashing Tool | SP Flash Tool |
Warning:
Never flash scatter files from S421T or S421 (MT6737T or MT6735) on an S421 MT6737M—wrong firmware can cause black screen, permanent dead boot, or loss of touchscreen. Avoid “Format All + Download” options unless the device is seriously corrupted.
Download Official Firmware for Positivo S421 MT6737M
Restore soft-bricked, bootlooped, or FRP-locked Positivo S421 MT6737M using the factory scatter firmware (verified for this model).
Firmware:
📄 Filename: Positivo_S421_MT6737M_05012017.zip
📦 Size: 991.86MB
⬇️ Download Link (MediaFire)
How to Flash the Firmware
- Extract Positivo_S421_MT6737M_05012017.zip to access scatter and firmware files.
- Install MTK VCOM USB drivers (Windows). Download and open SP Flash Tool.
- In SP Flash Tool, load the scatter file. Power off phone, remove battery, then connect USB.
- Click “Download” to start flashing; wait for “Download OK” message. First boot after flash will take longer than usual.
- If phone remains dead, try only “Firmware Upgrade” mode, or check battery and cables.
For detailed SP Flash Tool video and troubleshooting tips, visit: this MTK flashing guide.
