After the tool says "Pass," the phone will reboot to a black screen for up to 10 minutes. Do not press any buttons. It is rebuilding the cache. Eventually, you will see the Asus logo, then the Android setup wizard.
Congratulations! Your ZenFone 5Z is now running pristine raw firmware. asus zenfone 5z -zs620kl raw firmware-
Asus implemented an Anti-Rollback index on the ZenFone 5Z. If you try to flash an older raw firmware version than what is currently on your device, you will permanently hard brick the phone. A hard brick means no fastboot, no recovery, no life. Only a JTAG repair (costly motherboard replacement) can save it. ASUS Zenfone 5Z – ZS620KL Raw Firmware Digest
Always check your current firmware version before flashing raw firmware. Step 6: First Boot (Patience is key) After
Sometimes a new update introduces bugs or removes features. OTA updates often do not allow you to downgrade (go back to an older Android version). Raw firmware allows you to wipe the current OS and flash an older, stable version (e.g., going from Android 10 back to Android 9).
| Error | Possible Fix |
|-------|---------------|
| Sahara fail (QFIL) | Reinstall Qualcomm HS-USB QDLoader 9008 driver. |
| Invalid sparse file format | Convert system.img to raw: simg2img system.img system_raw.img |
| Partition table mismatch | Use exact raw firmware matching your SKU (WW_ZE620KL, CN, etc.) |
| Device not detected in EDL | Short EDL test points or use Deep Flash Cable. |