Error Max Temp Bed

[lalink]

I recently bought a Geeetech prusa i3 and just finished putting it together and installing Repetier Host. I followed instructions on how to set up the software with the machine but I encountered the error message "Printer stopped due to errors. Fix the error and use M999 to restart." The LCD displays "ERR MAXTEMP BED." I have read through some posts with the same problems and checked for short circuitry within the board but can't seem to find any problems. Here's a picture of the circuit board if anyone can help.

[zhangxueyou]

I notice that you connected the endstops wrong, the wires should be connected to "SIG" and "GND".
What is the LCD displaying after you swap the connection of 2 thermistors, namely, connect hot bed thermistor to "E-THERM" and connect extruder thermistor to "B-THERM"?

[lalink]

The display now reads "Err: MAXTEMP" and Repetier-Host gave an error message as follows:
"Error: 0
Extruder switched off. MAXTEMP triggered!
Error: Printer stopped due to errors. Fix the error and use M999 to restart."

[zhangxueyou]

Please check if somewhere of hot bed thermistor is short circuit.
If you have a multimeter, please test the resistance of thermistor, it should be around 100k ohm in room temperature.

[lalink]

Sorry I am a noobie, but is the thermistor the wires under the tape on the heat bed?

[zhangxueyou]

Yes, that's it.

[lalink]

I've used a DMM to measure the resistance of what I believe is the thermistor, but I get no readings on the DMM.

[zhangxueyou]

Did you unplug the wires from mainboard to measure it?
What reading do you get when you measure another thermistor?

[lalink]

I get a reading of 87.8 kilo-ohms from the bed thermistor when I turn on the machine without running the program. But now the error on the display reads "Err: MINTEMP"

[zhangxueyou]

I get a reading of 87.8 kilo-ohms from the bed thermistor when I turn on the machine without running the program. But now the error on the display reads "Err: MINTEMP"

The bed thermistor looks fine, when the temperature is 25 degrees, it's about 100k ohm.
Please check if extruder thermistor is well connected. When LCD displays "err: mintemp", extruder thermistor is not well connected to mianboard, or it's open cricuit somewhere.