I have my A1 plugged into a soecial surge protector that provides power to the rest of the outlets if the one trigger outlet draws enough power. So the printer is always on so that I can send stuff to it but doesn’t draw a lot of power. When it’s heating up and printing the power draw increases enough to trigger the rest of the outlets and a desk lamp turns on so I can see what’s being printed better. This is especially helpful at night when the desk lamp is the only light in the small office my printer is in. It’s been set up like this for 2 years and it’s been great.
This morning I was not actively printing anything and I went into the office and the desk lamp was on. I looked at the printer and it wanted to update the firmware, so I did so. Afterward the lamp stayed on. I rebooted the printer multiple times and while it’s rebooting obviously the lamp is off and when it boots back up the lamp stays on.
What is causing this increased power draw? Any ideas or insights?
For now I’m leaving it fully off but I’ll have to manually go in and turn it on before sending something to print which is less convenient.
Yes, even when the sensor fails.
If the feedback from the thermistor is either nonsense or doesn’t change as expected even when the heater is on/off for a certain time, that should trigger a thermal runaway error and halt the printer. That’s basic decade plus old Marlin code.
I’ve had two broken thermistors in my Ender 3. First one reported negative temperatures when it disconnected, so the printer immediately halted with a min temp error. The second reported something like 150C, which was in the acceptable range, except when it tried to heat it up and nothing changed for like 15 seconds, which triggered a halt.
Again, decade old marlin code. Not rocket surgery.