Geeetech

I had a short between the two wires of the thermistor on my A10 that resulted in a dead GT2560. I replaced that board, but now the E1 temp shows as -14C and when I try to start a print it heats the bed, then fails with a "HEATING FAILED PRINTER HALTED please reset" error on screen.

I've since replaced the extruder extension board an the hot end. The only hardware piece I haven't replaced is the cable from the GT2560 to the extension board. And I've checked all of the connections and reseated them just to make sure. Does anyone have any suggestions as to what I should check/try next?

Hi，You may need to check your hot end thermistor wiring.
Determine if it is fully accessible,
If you are accessing, you can try to measure the thermistor at the hot end.
I hope this can help you.

As I noted in my original post I've checked and reseated all of the wiring, so this isn't a loose wire issue. And the hot end is brand new, and came with the thermistor and hot end heater wires already attached. Is there anything besides that that could be causing the incorrect temperature reading? With a new extension board, a new gt2560, and a new hot end, the only other hardware I could replace is the cable from the gt2560 to the extension board.

Hi, If the temperature is shown as a negative value,
the thermistor of the hot end may not be fully connected or damaged.
You can measure your hot end thermistor.

I am also starting to experience some extruder heating issues. The extruder temperature has been stable at 193 but during the last brint it has started varyingh between 170 - 220, and jumping around a lot. Is there a place to find tips on how to test this, to look for shorts and poor connections? Could it also maybe be a PSU voltage issue?

Hi,You can check if your hot end thermistor is fully connected.
It can be measured with a multimeter.