If the warming is failing, the issue will be the fuser, so remove the fuser and boot it up to discount that part as the issue or to confirm it
we've got a 3320 here that won't power up anymore. When turning it on, it just displays "Warming Up - Please wait", green and orange LEDs are on. Then after a few seconds, the lights and message turn off quickly, and it all repeats.
Support told me that we'll have to pay 400-500€ (without even knowing what the issue was..), so I guess we're on our own. Any idea?