Hotend Heater won't activate

[Oddstag]

Hi there, would greatly appreciated assistance with an issue I'm a little stumped by. I have a Duet 6HC with 3HC expansion board. I have my toolhead wiring hooked into the expansion board, including the hotend heater. I seem to have no problem with my CAN connection as I am able to control toolhead fans and get input from the z probe that are present there but I simply cannot get my hotend heater to respond at all. I can't activate it via DWC and M104 fails with an error saying simply that the temperature isn't increasing (no kidding). Thermistor attached to the heater seems to be functioning normally. I've confirmed continuity with a multimeter between the two pins

Here's is the relevant section of my config but do let me know if more info would help.

; Heaters
M308 S0 P"temp0" Y"thermistor" T100000 B3950            ; configure sensor 0 as thermistor on pin temp0
M950 H0 C"out0" T0                                      ; create bed heater output on out0 and map it to sensor 0
M307 H0 B0 R0.812 C329.6 D3.71 S1.00 V24.0              ; disable bang-bang mode for the bed heater and set PWM limit
M140 H0                                                 ; map heated bed to heater 0
M143 H0 S120                                            ; set temperature limit for heater 0 to 120C
M308 S1 P"1.temp0" Y"thermistor" T100000 B4725 C7.06e-8 ; configure sensor 1 as thermistor on pin 1.temp0
M950 H1 C"1.out0" T1                                    ; create nozzle heater output on 1.out0 and map it to sensor 1
M307 H1 B0 S1.00                                        ; disable bang-bang mode for heater  and set PWM limit
M143 H1 S280                                            ; set temperature limit for heater 1 to 280C

[deckingman]

@Oddstag You don't have any PID parameters for the heater. Have you tried running a heater tune? If it fails to heat when doing a heater tune, and you are sure the wiring is good, then the only thing left is the heater itself. Have you measured it's resistance?

[droftarts]

@Oddstag as well as what @deckingman said, your config says the heater is connected to out0, check it is connected to that output.

Ian

[A Former User]

@Oddstag I'll assume you have your PID tune in config-override.g which is where mine are. Your config other than can address is exactly like mine. If your heater is connected to 1.out0 then maybe the mosfet is bad or the firmware versions do not match? I know on mine when the RRF-36 toolboard was 3.5.0-rc.1 with the mainboard being 3..4.6 I could run the fans and see the temperature but not control the BLtouch or heater.

[Oddstag]

@KenW

You brilliant bastards, you've done it again. This was it. Expansion board was slightly behind the mainboard. Thanks for all the great suggestions gang.

For future generations:

M115 to check mainboard firmware version.
M997 to update firmware on mainboard
M115 B1 to check firmware version on expansion board at CAN address 1.
M997 B1 to update the expansion board.