Thermistor issue....
-
Hi,
since this morning i have a issue with thermistor.
In DWC can read temperature of 2000, this means some problem with thermistor, yesterday was fine.
The first test i have do, its change the Thermistor by a new thermistor.... but nothing the read in DWC, the same, 2000.
Second test its connect bed thermistor in extruder thermistor... and the read its the same 2000.
Third test its connec extruder thermistor, that reads 2000 in DWC, in bed shocket, and temperature reads ok...i have these lines in config,g
M305 P0 S"Cama" T100000 B4138 C0 R4700 ; Bed M305 P1 S"Extrusor" T100000 B4138 C0 R47000 ; Nozzlewhat can i do?
Dont seems thermistor issue. Can be a Duet problem? -
measure the resistance of the thermistors with a multimeter at the molex connector.
-
hi,
i think there is not thermistor problem.... why. When connect the bed thermistor, that works, in Nozzle socket, the read in DWC its 2000º...
But i have meassure the resitance:
- Old thermistor 87,2 kOms
- New thermistor; 81,2 kOms
-
exist some procedure for check the Duet shockets?
Duet, has another shocket for thermistor. No?What i have to do... for assign the reading of this shocket, to extruder.... and first, how i can see what its reading this shocket?
In this moments, i have connected Nozzle thermistor in E1
-
One thing I forgot to comment, important.
About a week ago, I had extrusion problems ... after doing several tests, I saw that the temperature Duet read was about 25 degrees higher, than it actually was in Hotend. I solved it, raising those 20 degrees the temperature ... So, the PLA, which printed at 205 degrees, raised it to 225 ... with this it worked ...
-
@peirof said in Thermistor issue....:
About a week ago, I had extrusion problems ... after doing several tests, I saw that the temperature Duet read was about 25 degrees higher, than it actually was in Hotend. I solved it, raising those 20 degrees the temperature ... So, the PLA, which printed at 205 degrees, raised it to 225 ... with this it worked ...
that is because you have not configured your thermistor correctly. B4138 is the default and you need to put in the beta value that is correct for the type of thermistor you are using.
since the thermistor is working you have probably blown the vssa fuse. see
https://duet3d.dozuki.com/Wiki/Connector_and_spare_part_numbers#VSSA_fuse -
your R value for the nozzle is wrong and that is probably what is causing your issues try setting it to R4700 you have one to many 0 in yours
-
@dougal1957 was this.... in some moment, i have put a 0..... its strange, a 0 has not valour.....
thanks and sorry
-
If you've checked the thermistor wiring and you're getting sensible readings at the connector, and your config.g is correct, the quickest way to test the Duet thermistor input is to connect a known-value resistor, preferably one that matches the value it expects from config.g.
For example, my bed thermistor setting is 'M305 P0 T100000 B3988 C0 R4700'. A 100k ohm resistor reports 24.7C, a 10k ohm resistor reports 87.1C. I keep a couple handy for exactly this, it's a quick way to check config.g settings are correct and Duet is working correctly!
Ian
