The "25q32fv" in your request refers to a 4MB Winbond flash chip. Standard firmware for other versions might require a 2MB or 8MB chip; verify your hardware version (e.g., v1.2, v2.1, v2.5) before flashing 4PDA .
If you manage to restore the firmware, the default admin login is typically admin / admin Wind Manual .
If you are looking to replace the stock software with open-source firmware, the OpenWrt ZTE H108N page provides technical data and installation guides via CFE web recovery.
Note: It is explicitly warned by OpenWrt that models with 8MB Flash/64MB RAM (like many H108N variants) are not recommended for future versions of OpenWrt due to limited resources. Important Technical Checks