Hi,
Second extruder in my prusa turns on automatically with out any command when power supply is turned on.
I'm using printrboard Rev D with Dual extruder board and FW is marlin.. If no USB connection is established( USB is not connected to USB port ) and power supply is ON , second extruder turns on automatically and temperature increases without any limit. It already melted two of my j head hotend assembly. First extruder doesn't have any issue. But if the USB is connected to port (doesn't require connection with host, i.e., Repetier) and supply is turned on, then there's no temperature rise.
Supply USB connection Extruder 1 Extrude 2
OFF OFF OFF OFF
ON OFF OFF ON
OFF ON OFF OFF
ON ON OFF OFF
Shouldn't second extruder be OFF in all condition unless it's turned by either command or manual control in Repetier
I made a video of what's happening
video
In the video, power supply is already on(not shown in video) As you can see when only the power is turned ON and no usb connection established(usb cable is not connected to usb port), second extruder starts heating up, when connection is made(you can hear the sound as I plug in USB cable) you can see the current extruder temp( extruder 1 is at room temp but extruder 2 is not ). But as soon as the connection is made temp increase gradually reduces and finally stop then return to the room temperature(not shown in video because of size limitation). But if I remove the usb cable again, temperature starts increasing.
I changed the dual extruder board with new one also changed the ribbon cable connecting Printrboard and Dual extruder board , re-flashed FW, even swapped hotends , but no matter what hotend connected to the dual extruder board heats up when supply mains is turned ON if USB is not connected.
I don't have a spare Printrboard to check..
Could this be due to any issue with Printrboard?
Anyone else had issue like this?
AS far I remember this won't happened before. Both extruders were off when the power is ON and USB is not connected(But I'm confused, I can't remember)
But it shouldn't turn ON. It takes less than 10 seconds to increase temp from 30 degree to 100 degree
Thanks
