If the universal ALC#FGU password does not work, your Internet Service Provider (ISP) may have changed the default credentials or disabled super admin access remotely.
Some providers use combinations like telecomadmin / admintelecom or stcroot / STC@12345 . nokia g1425ga super admin
While the label on the bottom of the device provides a basic account, a "super admin" account (often termed AdminGPON ) is required for full control over fiber ONT settings. If the universal ALC#FGU password does not work,
Always check the sticker on the bottom or back of the router first; some newer G-series models now print a unique administrative password there. nokia g1425ga super admin