If your region isn't listed, use the D-Link Global TSD site to search for the specific "J1" revision. Installation Instructions
Follow these steps exactly. Do not skip any.
Given these constraints, sticking with stable official firmware is recommended. Users seeking more advanced features might need to consider more modern hardware. d-link dsl-2750u h w ver j1 firmware
Updates the ADSL modulation protocols to work better with modern Internet Service Provider (ISP) exchanges.
Open a web browser and type 192.168.1.1 (the default gateway) into the address bar. If your region isn't listed, use the D-Link
Disclaimer: Firmware updates are performed at your own risk. Always ensure a stable power supply during the update process.
The router will begin updating. turn off the router or close the browser window. Open a web browser and type 192
The new firmware changed your DSL modulation mode. Fix: Go to Advanced Setup > DSL and try different settings: ADSL2+ , VDSL2 , or Auto Sync . Some J1 units require G.DMT for legacy lines.