Heater 0 and Heater 1 reading 2000°C

Danal

@CaiJonas said in Heater 0 and Heater 1 reading 2000°C:

I think my WiFi board is falty, temp always 2000°C.

Unplug that temp sensor completely. Still read 2000?

A Former User

Danal said in Heater 0 and Heater 1 reading 2000°C:

Debugging step: Measure the resistance of each sensor Using a DVM or similar

Indeed! If they measure about 100kΩ at 20°C they should be ok and then carefully without shorting any pins measure from ground on say the Vin terminal to both pins of the thermistor input and report back readings.

Bakak

FIRMWARE_NAME: RepRapFirmware for Duet 2 WiFi/Ethernet FIRMWARE_VERSION: 2.03 ELECTRONICS: Duet WiFi 1.0 or 1.01 FIRMWARE_DATE: 2019-06-13b2

; Configuration file for Duet WiFi (firmware version 2.03)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool v2.0.4 on Sat Oct 12 2019 17:04:55 GMT+0200 (Mitteleuropäische Sommerzeit)

; General preferences
G90                                         ; send absolute coordinates...
M83                                         ; ...but relative extruder moves
M550 P"Predator"                            ; set printer name
M665 R220 L440.4 B185 H420.607                  ; Set delta radius, diagonal rod length, printable radius and homed height
M666 X0 Y0 Z0                               ; put your endstop adjustments here, or let auto calibration find them

; Network
M552 S1                                     ; enable network
M586 P0 S1                                  ; enable HTTP
M586 P1 S0                                  ; disable FTP
M586 P2 S0                                  ; disable Telnet
M575 P1 B57600 S1				;Serial Port for Panel Due

; Drives
M569 P0 S0                                  ; physical drive 0 goes forwards
M569 P1 S0                                  ; physical drive 1 goes forwards
M569 P2 S0                                  ; physical drive 2 goes forwards
M569 P3 S1                                  ; physical drive 3 goes forwards
M584 X0 Y1 Z2 E3                            ; set drive mapping
M350 X16 Y16 Z16 I1
M350 E16 I1                     ; configure microstepping with interpolation
M92 X160.00 Y160.00 Z160.00 E412;  E399	    ; set steps per mm
M566 X600.00 Y600.00 Z600.00 E160.00  ; set maximum instantaneous speed changes (mm/min)
M203 X18000.00 Y18000.00 Z18000.00 E10000.00 ; set maximum speeds (mm/min)
M201 X2000.00 Y2000.00 Z2000.00 E1000.00    ; set accelerations (mm/s^2)
M906 X1000 Y1000 Z1000 E800 I50             ; set motor currents (mA) and motor idle factor in per cent
M84 S30                                     ; Set idle timeout

; Axis Limits
M208 Z0 S1                                  ; set minimum Z

; Endstops
M574 X2 Y2 Z2 S1                            ; set active low and disabled endstops

; Z-Probe
M558 P5 R0.4 H20 F1200 T6000 A10 S0.02                 ; set Z probe type to effector and the dive height + speeds
G31 P100 X0 Y0 Z-0.13                           ; set Z probe trigger value, offset and trigger height
M557 R180 S18                               ; define mesh grid


; Heaters
M305 P0 T100000 B4138 C0 R4700                 ; set thermistor + ADC parameters for heater 0
M143 H0 S120                                ; set temperature limit for heater 0 to 120C
M305 P1 B4725 C7.060000e-8 R4700                ; set thermistor + ADC parameters for heater 1
M143 H1 S280   
;M305 P2 B4725 C7.060000e-8 R4700                ; set thermistor + ADC parameters for heater 1
;M143 H2 S280                                ; set temperature limit for heater 1 to 280C

; Fans


M106 P0 S0 F100  C"Bauteillüfter"                    ; set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P1 S0.66 H1 F100 T60 L0.3 X0.75              ; set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned on

; Tools
M563 P0 D0 H1 F0                            ; define tool 0
G10 P0 X0 Y0 Z0                             ; set tool 0 axis offsets
G10 P0 R0 S0                                ; set initial tool 0 active and standby temperatures to 0C

; Custom settings are not defined
M98 P0:/sys/retract.g
T0
M501
M572 D0 S0
G29 S1

I'm measuring 120k for the hotend Thermistor and 114k for the Bed thermistor, which should be fine....

I mesaure a Voltage of 3.2V from Thermistor0-pin, Thermistor1-pin and Thermistor2-pin to GND. ---However, the VSSA voltage is slowly crawling from 3.2V to 0V while i measure between VSSA and GND. shouldnt VSSA be GND potential?

edit: i just noticed... there is a resettable fuse F1... how do i reset it?

dc42

@Bakak said in Heater 0 and Heater 1 reading 2000°C:

I mesaure a Voltage of 3.2V from Thermistor0-pin, Thermistor1-pin and Thermistor2-pin to GND. ---However, the VSSA voltage is slowly crawling from 3.2V to 0V while i measure between VSSA and GND. shouldnt VSSA be GND potential?

Yes, VSSA should be only a few millivolts above ground unless there is a short circuit between VSSA and a higher voltage. The polyfuse connects VSSA to GND. It is self-resetting.

A Former User

@Bakak said in Heater 0 and Heater 1 reading 2000°C:

there is a resettable fuse F1... how do i reset it?

it should as dc42 said self reset; to test it power off the board and measure resistance F1 it, should probably be in the 0-1 ohm range if working.

Bakak

Overload... i guess it broke -.-

Bakak

What type of fuse is this?
I'm confident, that i can replace it

A Former User

@Bakak said in Heater 0 and Heater 1 reading 2000°C:

Overload... i guess it broke -.-

may sound silly but double check you have a 0 reading when shorting the leads, and make sure to apply some pressure to pierce any oxide layer on the solder joint.

@Bakak said in Heater 0 and Heater 1 reading 2000°C:

What type of fuse is this?
I'm confident, that i can replace it

shematic says:

Fuse to protect the SAM from VIN applied to VSSA in error.
Multicomp MC36207, Bel Fuse 0ZCJ0020FF2E

Bakak

yep. just measured again in high ohm range, 15M.

thanks for your help, this saves me a ton of money

CaiJonas

@droftarts I'm using the latest release of ReprapFirmware 3, upgrading was the first thing I did. All other things works just perfekt.

@Danal with unplugged sensor it also shows 2000

@dc42 what could I do to test, what is the problem?

Thanks to all so far

dc42

Bourns MF-MSMF014 is another suitable part number for the VSSA fuse. You can solder the new fuse on top of the old one, which will be easier than trying to remove the old one.

I've never heard of the VSSA polyfuse failing before.

As a temporary workaround, you could connect VSSA on one of the thermistor connectors to GND on one of the endstop connectors. But then you lose the protection against a thermistor short to VIN, which is what the fuse is there to protect against.

Bakak

haha! finally i'm the first to achieve something

I just ordered some of the fuses. don't want to run the board unprotected

A Former User

You don't need a poly fuse or even a surface mount one, any odd fast acting 100mA or so fuse could be either wired between VSSA and GND or solderd in parallell with the existing one would provide protection.

CaiJonas

@Bakak @dc42 I don't get it, what fuse can I measure and what should the value be?

Bakak

(

this one.

dc42

@CaiJonas said in Heater 0 and Heater 1 reading 2000°C:

@Bakak @dc42 I don't get it, what fuse can I measure and what should the value be?

What revision is your Duet WiFi?

If it's 1.0 or 1.01 then see https://duet3d.dozuki.com/Wiki/Connector_and_spare_part_numbers#Section_VSSA_fuse.
If it's 1.02 or later then the polyfuse is the green component between the processor and the WiFi module.

Please check that you are still getting 2000C readings even with just USB power applied (no VIN power).

CaiJonas

@dc42 I measured a value of 1.1-1.2 ohm and I still get 2000°C readings with just USB power applied.

dc42

If you disconnect the thermistors completely and use your multimeter to measure the voltage between the two pins of one of the thermistor connectors, with USB power applied, what voltage does it read? Does it still read 2000C or does it change to -273C ?

CaiJonas

@dc42 I measure excactly 3.3V on all three channels and temp stay on 2000C. Do you have a presumtion what the Problem could be?

dc42

It sounds like either a failure of the main processor (but this type of failure would be very unusual) or a configuration problem. Please post your config.g file.