Toolboard LC1 - Temp0 with offset or wrong reading

Marshal

Hello All,

I am setting up a new printer with my first set of Duet Hardware and RRF.
I am using a Duet 3 and currently 1 Toolbaord LC1 without distribution board.

Duet 3:

Board: Duet 3 MB6HC (MB6HC)
DSF Version: 3.2.2
Firmware: RepRapFirmware for Duet 3 MB6HC 3.2.2 (2021-02-11)

Can and power connection between Duet3 () and LC1 is up:

M115 B121
Duet TOOL1LC firmware version 3.2 (2021-01-05)

Currently I am faceing an issue with the reading of Temp0 on the LC1.
For testing and debugging I have configured 3 thermistors (104gt-2), 1 on the Duet3 and 2 on the LC1:

M308 S0 P"0.temp0" Y"thermistor" T100000 B4725 C7.06e-8;
M308 S1 P"121.temp0" Y"thermistor" T100000 B4725 C7.06e-8;
M308 S2 P"121.temp1" Y"thermistor" T100000 B4725 C7.06e-8;

The readings without connected thermistors are:

S0 = -273,1 C
S1 = 46.0 C
S2 = -273,1 C

Connecting a thermistor will result in:

S0 = ~26 C
S1 = ~163 C
S2 = ~26 C

Where 26 C is a little above room temperature and i consider as correct reading.

So it is not realy an offset.
Is there anything i can check or try
I have measured the resistance between pins 1 and 2 (don't know if this is helpfull)

LC1.Temp0 = 265 k Ohm
LC1.Temp1 = 4,4 k Ohm

Might the board/temp0 be fried?

Thanks
Marshal

dc42

@marshal, I'm sorry, it does look as though there is a hardware problem on that tool board. I've measured the resistance between pins 1 and 2 on a couple of tool boards that are not connected to anything, and both read about 4.4k across the TEMP0 pins.

My guess is the resistor R21 is not properly soldered at one end. If it's a version 1.0 tool board then R21 is right next to the TEMP0 connector, the second component in from the edge of the board. Does it look all right?

Marshal

@dc42 R21 seems to be in place. I checked resistance of the component and it is the same as for the pins.

Btw. it is version 1.0

dc42

@marshal said in Toolboard LC1 - Temp0 with offset or wrong reading:

@dc42 R21 seems to be in place. I checked resistance of the component and it is the same as for the pins.

Btw. it is version 1.0

R21 should have value 2.2K. The left hand end should be connected to the lower terminal on the thermistor block, and the right hand end to the other nearby components as seen here.

Marshal

@dc42 I have recieved a replacement today. New board is working as expected.
(SMD soldering is not on my stronglist )

Thx for your support.

dc42

@marshal, thanks for the update. I'm glad this is resolved.