Different Thermistor readings from Duet2 Wifi and Duex5

[sph711]

The thermistors for Tools 2 and 3 read about 10° while the thermistors for the bed and Tools 0,1 report 26° which corresponds well to my room temperature. The thermistors for tool 2 and 3 are both connected to the duex 5, while the others are connected to the duet 2. When I change the thermistor cables from the Duex to the Duet 2, it reads the correct value, so the thermistors themselfes are fine (I also checked the resitance of the individual thermistors and consistently get around 93kOhm). Is this a firmware issue or a hardware failure on the Duex board? The configuration in "config.g" is the same for all four thermistors as per default configuration from the Toolchanger RepRap firmware provided by E3D.

Can somebody help me pinpoint the issue?

Cheers,
sph711

[dc42]

@sph711 recent DueX5 boards use a lower value series resistor, so as to work better with PT1000 sensors. If you are running RepRapFirmware 3.4 and you don't have a R parameter in your M308 command, this should be handled automatically. Otherwise, you need to adjust the M308 commands for thermistors attached to the DueX5. See https://docs.duet3d.com/Duet3D_hardware/Duet_2_family/DueX2_and_DueX5#pcb-revision-history.

[sph711]

@dc42 Thank you. That fixed the issue. I went on to hot titghtening my extruders and noticed that the hotend and part cooling fan, connected to "fan1" and "fan2" are not turning on. They also do not work when plugged into the "always on" fan outputs of the duet (2 wifi).

The fans wired on the duex are all working well and they are all configured similarly in my "config.g". Do you have an idea on why this might be the case?

Sorry if this is a stupid questions. This is my first experience dealing with firmware issues.

Cheers,
sph711

[dc42]

@sph711 I suggest you check the 1A fan fuse on the Duet for continuity.