Controller Port/ F1 Fuse

[BloodBrother]

Hello Gents. Yesterday I found out the controller ports #2, 3 and 4 do not work while i was trying to play Powerstone with my brothers and sisters.
Now i have researched on this, and intend to follow Kazade's guide to fix it. This post is just to comment on the oddity of the situation.
If the F1 fuse is blown, would not any of my ports work? I ask because while the controllers dont work in those ports,there is power going through that lights up my 4x memory card, in those ports. Something i thought was weird. Additionally, my Dreamcast's LED hasnt worked in about a month, but when i plugged in the second controller, it lit up like christmas. Again, this isnt a please help fix it post, just looking to gain an understanding on the weirdness. If anyone has a theory I'd appreciate learning on whats going on.
*I admit, it must have been me that blew the fuse, as i learned while researching this that plugging/unplugging controllers w/ power on is a no-no. Something i know for a fact i do.

Thank y'all for your time!

[XVO]

I can't give you a theory why this is happening, but if it happened to my dreamcast I would first try to desolder the fuse and test it with a 10 ohms resistor.
If that works I'll buy a 72V 400mA Radial Lead Type PPTC to replace the resistor with.
If all of the above doesn't work I would check the traces on the board.

I'm more like a trial-and-error sort of guy

[TacT]

plugging and unplugging controllers while the power on is perfectly fine, I do it all the time for years and never blew a fuse in many dreamcasts and have abused this theory plenty.
The fuse is to protect against short circuits from damaging the dreamcast, if the fuse is blown its correct that None of the controller ports would work, and should not effect the LED working. It might be a busted ribbon cable from the controller board to the main board or not making good connection. If a controller or device consistently blows the fuse then the controller or device is busted and has a short most common is broken controller wires.
If the LED Is having problems it might be a power issue, try removing the power supply and cleaning the pins for better connection.

[Mechanic]

Or just swap the controller board with a known good 1 and make sure nobody runs over the controller wire with a powerchair I laugh cause it happened to me. Except in my case the ports were dead