The D-Link DSL-3890 (often branded as the AC2400 Wireless VDSL2/ADSL2+ Modem Router) is a high-performance device used by many Internet Service Providers (ISPs). Updating the firmware can improve Wi-Fi stability, fix security vulnerabilities, and resolve connectivity drop-outs.
Direct example format (not real-time link):
https://support.dlink.com/resource/products/DSL-3890/DSL-3890_fw_v1.02.bin dsl3890 firmware link
Call your provider’s technical support. Say: “My DSL3890 router is on firmware version [X], and I need the direct download link for the latest stable release. The link on your portal is broken.” A good agent will email you a secure link or send the firmware via a support ticket. D-Link DSL-3890 Firmware: Download Links and Upgrade Guide
Updating the firmware is a straightforward process that takes about five minutes. Say: “My DSL3890 router is on firmware version
Before clicking a download link, check the sticker on the bottom of your router. You will see a Hardware Version (e.g., H/W Ver: A1). Firmware is coded specifically for these hardware revisions; an "A1" firmware will generally not work on "B1" hardware. How to Update Your DSL-3890 Firmware