Greetings,
I do not believe there is a way to reset the device if the printer does not successfully boot or the web UI is unavailable.
Canon : PIXMA Manuals : TS8300 series : Reset setting
You did the correct thing, disconnecting from power and trying the restart. If a power event preceded this behavior, Its likely the printer will require service or replacement.
~Rick
Bay Area - CA
~R5 C (1.0.6.1) ~RF Trinity, ~RF 100 Macro, ~RF 100~400, ~RF 100~500, +RF 1.4x TC, +Canon Control Ring, BG-R10, 430EX III-RT ~DxO PhotoLab Elite ~DaVinci Resolve ~Windows11 Pro ~ImageClass MF644Cdw/MF656Cdw ~Pixel 8
~CarePaks Are Worth It
