>Blowing a fuse is irreversible— once it’s been set it can never be undone. Sounds impossible, until you find out that if you don't blow them hard enough you c

>Blowing a fuse is irreversible— once it’s been set it can never be undone. Sounds impossible, until you find out that if you don't blow them hard enough you can get fuse re-flow under hot conditions. Good fun to debug. In theory (untested to my knowledge), if you super cool the chip you could lower the resistance of the fuse and prevent it from blowing and absorb heat around the fuse, but it's probably not all that practical for casual game players. As for getting to the problem at hand (force downgrading your system), some potential solutions (nothing easy): * Careful control over the chip's power and you could perform a power supply timing attack, tricking the processor logic. This seems like a bit of a stab in the dark though. * Assuming the bootloader is loaded into some form of RAM, you could look towards modifying the RAM as the chip boots to contain some kind of "skip" code for set pins. Game consoles have hardly been beyond the realm of needing mod-chips to access different features... * The other option would be to replace the chip containing the bootloader with a non-upgraded one.