HEAT BED STAYS ON

Heat Bed stays ON


When I switch on the power to my RAMP 1.4 on my prusa type design machine, the heat bed led comes on and the heat bed starts to heat up. It then stays on at the required temp until I turn the system off.


I am using Arduino, Marlin, Proterface and Slic R3. My ramps 1.4 is linked to a LCD controller


What have I done wrong !!

Are you saying it goes beyond your intended temperature, or does it reach the target and then cycle on and off? If the first, then that is a problem. If the second, then its not a problem - that's the way it works. The hot bend remains heating until you explicitly turn it off.

I don't know what slicer you are using, but I use skeinforge, and I have a bit of custom end g-code that, among other things, turns my bed and hot end off

Thanks for your email

As soon as i switch the main power on the heat bed starts to heat up and stays on all the time at about 80 degrees to i switch the power off

ie gets hot before i have done any work and before i open up pronterface etc

thanks


Paul

Sounds like the FET has failed to a short, OR your microcontoller has embedded code to fire up the heater upon powerup.

Thanks will check both

Paul