error MINTEMP 0/0° 0/0° HELP PLEASE

[Raffo1000]

Hi,
I'm Raffaele and I bought a Geeetech Prusa I3 pro B 3D printer a week ago but at the first start it gives me this error: MINTEMP, extruder and hot bed both 0/0° (see the photos). I check the connections and the cables they seems OK (but i didn't strip them). Is it possible that GT2625 is defective?
i tried to move axis and they are OK except the extruder motor, it doesn't work and remains motionless when I turn the knob. what I have to do ?

Thank you !

[Raffo1000]

the mother board il 2560 of course.

[William]

Hi,you can check whether the screen cable is connected properly and burn the firmware again.
If it still shows like this, maybe there is a problem with the thermistor of the extruder and the hot bed.
Can you provide the pictures after the main board is powered on?

[Raffo1000]

Hi William,thanks for the reply.
I checked the screen cables and thay are OK. These are the photos of the turned on card.

I don't know if the problem is the thermistors, I read here , (viewtopic.php?f=13&t=17030) that if I short the thermistor sockets I should have the MAXTEMP error, instead the MINTEMP error always appears to me.

Do you confirm that if I short the thermistor sockets I should have the MAXTEMP error?

If this is true the problem is the motherboard?
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[William]

Hi,you can unplug the motor cable on the extruder to check whether the main board is in good condition.

If the temperature display is - 14 ℃ after unplugging the motor wire, it proves that the main board is good,

That's a thermistor failure.

[Raffo1000]

Hi,you can unplug the motor cable on the extruder to check whether the main board is in good condition.

If the temperature display is - 14 ℃ after unplugging the motor wire, it proves that the main board is good,

That's a thermistor failure.

Hi,
I have unplugged the motor cable on the extruder , like in the photo, but the LCD always shows the same temperatures (0/0° and 0/0°).
I need to change the card?

[William]

Hi,unplug the extruder cable to display 0 ℃, maybe there is a short circuit somewhere on the main board.
you should contact the salesperson on the purchase platform to change.