Duet Problems again

So, I was working on my extruder when i look at my hot end temp and it was reading 280c and climbing when it was set to 210c . So i shut off the power disconnect the heater and temp prob turn it back and now i can not connect via web and it is not pulling a IP. I can connect using USB i have flash it with the new DC42 firmware and updated the SD card and Pronterface kind of works . Still cant connect so i check the Atmel chip and its burn my finger hot form what i have read that is not a good sign . So is my board dead? and if so why?

It sounds as though you may have had a short between one of the hot end heater connections and one of the themistor connections. Or possibly you have an internal short in the heater cartridge between the heating element and the casing (this happens sometimes) and you also have a short between the heater block and one of the thermistor wires. Take a look at component L7 on the Duet. If it is burned out then that confirms that a short of this or a similar kind occurred.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

L7 looks fine.