Most old RouterBoards have a serial header. Use a USB-to-TTL adapter and PuTTY to access the router directly—no Winbox required.
Resolving...
Despite being old, v2.2.16 includes the essential tools required to manage a MikroTik router: winbox old version 2.2.16 download
/ip neighbor discovery-settings set discover-interface-list=all Most old RouterBoards have a serial header
If you download from any source, always verify the SHA256 checksum. A clean version should match these (approximate—always confirm via multiple sources): winbox old version 2.2.16 download