Temp sensor min temp error

[Titus 170]

Hi all,

From the other threads I've seen on Min temp errors, this is a different one.

I encountered a min temp once when I came in from the cold and wanted to start printing. After it was warmed up to like 10-15 degrees it worked fine again.

However, I got a new temp sensor since the wires of the old one were kinda broken. When I power up my UM1, it shows 3 deg C, and within like a second or two it jumps to room temperature. BUT it gave a min temp error since it started on 3 dec C.

When I heat the nozzle up to like 90 deg C, and power off, power on, it starts on 20 deg C and jumps to 90, WITHOUT giving the min temp error since it never was below the threshold.

So it seems there is some kind of lag in the correct signal coming from the sensor. It's workable, but frustrating to having to power on, heat, power off, power on your printer before you can start printing. Anyone a clue how to fix it?

 

[gr5 2,271]

So it seems there is some kind of lag in the correct signal coming from the sensor.

 

I can't imagine how this could be true. This is very strange. I think you need a new PCB (printed circuit board) if you really want to fix this.

 

[tinkergnome 927]

...

I encountered a min temp once when I came in from the cold and wanted to start printing. After it was warmed up to like 10-15 degrees it worked fine again.

...

 

Well, there are minimal temperatures defined in the firmware - could this be related to this...? Seems to be another security feature...

From Configure.h:

 

// The minimal temperature defines the temperature below which the heater will not be enabled It is used

// to check that the wiring to the thermistor is not broken.

// Otherwise this would lead to the heater being powered on all the time.

#define HEATER_0_MINTEMP 5

#define HEATER_1_MINTEMP 5

#define HEATER_2_MINTEMP 5

#define BED_MINTEMP 5

If the printer works fine after it is "warmed up" this could be an explanation...

 

[Titus 170]

@TinkerGnome, editting those would most certainly work, but would there also be a risk I wonder.

@Gr5 The almost broken sensor does not lag, so it's probably not the PCB, but something internal in the sensor.

 

[Titus 170]

@Gr5, it now also starts to happen with my old sensor! I'll have a look into the PCB with my multimeter