I can't tell you which models, but once they go into an error code the Settings Menu may become inaccessible. And if you replace the printhead while...
World's Fastest Gun Disarm Man? (.08 second Victor Marx 7th Degree Black Belt)
World's Fastest Gun Disarm Man? (.08 second Victor Marx 7th Degree...
I've never seen the official bulletin, but it's no small task. On later production models they installed a new style front cover with holes to access...
If I were to guess, I'd guess that the U021 reset cleared the speed upgrade code, so it won't accept that toner, and it will run at 25ppm. I suspect...