HELP! Extruder heating up by itself, bed doesn't heat at all

Hi guys,

I faced a strange issue yesterday when trying to print ABS. Everything worked ok for the first 10-ish layers, then i saw that the print lifted, so I stopped it.
I'm using Octoprint and looking at the temp curve, I saw that 8 minutes before suddenly the bed temp lowered until like 50° which is the time when the print lifted.

Then strange things happened:
1. I wasn't able to set any temp on the bed, actually, I could set it, but it wouldn't heat up.
2. The extruder wouldn't react on switching it OFF ! I tried everything that I could, I even unplugged power from the printer itself. This was yesterday evening. This morning, I switched on power and the extruder immediately starts heating up without getting any command to do so. I don't get unrealistic readings though like in other posts.

Now, I'm not sure if anything might have broken or something can/need to be reset.
Any help appreciated!


UPDATE: After restarting the PI and starting all over, i.e. plug in power -> monitor temps, switching on -> monitor temps, heating bed -> monitor temps,... all is fine now. Back in business...

Update 2: ... too fast updating a couple of minutes ago , the bed temp dropped again and hosed my print.

Any clue why the bed temp drops? Maybe cura sends a command? Will try to set it manually

Update 3: My bed is stalling while heating up. The pic below: bright colors are preset temperatures while the bold colors are actual readings. Extruder works just fine, but the bed does not. It heats up until about 70° but then stalls without having gotten a command to do so. This is with manual pre-heating, no print yet.

Anything that I can check?


Thanks!

 

Hi guys,

after disassembling the bed and tighten the thermistor wich seemed somewhat loose, I was hoping that this would solve the bed heating issues, so I started heating the bed and extruder. but ater some 15min and about 6min into the print, the temperature dropped again.
Is the bed broken?
Any other hint appreciated.

Thanks!

 

thanks! Leon just pointed me to his thread about using a relay. Good to hear that nothing's really broken. I'm going to get a relay and a fan.