Hi
I just finished the k8400 kit and loaded the firmware M:1.0 V:1.1 HEADS:1.
Unfortunately the status screen shows me the error “Err: MAXTEMP” 
I checked the cables from the heater and the thermistor and I fixed the wrong connected wires…
But I still get the same error
Do you have any ideas, what’s wrong or defect?
PS: The thermistor is at 85kOhm
Thanks for your help!
Jan
Have you saved the config to the EEPROM after uploading the firmware?
Post a picture of your LCD screen.
Hi raby
I thought i will receive an email if you reply to my post, so i just now saw your reply 
by the time i bought a new sensor but i still get MAXTEMP error so please help me!!!
Which config should i save to the EEPROM?
here is the picture…
thanks in advance
jan
Your LCD doesn’t show any values, only zeroes…
Once the firmware uploaded you must go to the “Settings” menu on the LCD and select “Restore Failsafe” and click the button. Once this done go in “Settings” again, select “Store Memory” and click.
And you must use the 1.0.6 version of the Arduino software to upload the firmware and not the 1.6.x version which doesn’t work correctly with this firmware
I did as you sad and anything is still the same on the LCD!
I used 1.0.6 to upload the firmware… should i upgrade the firmware to 1.4 ?
[quote=“rj1”] should i upgrade the firmware to 1.4 ?[/quote]Certainly because it fixes an important bug.
Was your printer powered on when you took the picture of your LCD or only connected to the USB?
i upgraded to 1.4 and still the same on the LCD
yes, i got the same results on the LCD with usb connected or only with 230V Power…
what does “Restore failsave” and “Store memory”? I didn’t read anything about that on the Manual while assembling the Vertex K8400.
and thanks for your help by the way 
cheers jan
[quote=“rj1”]i upgraded to 1.4 and still the same on the LCD
yes, i got the same results on the LCD with usb connected or only with 230V Power…
what does “Restore failsave” and “Store memory”? I didn’t read anything about that on the Manual while assembling the Vertex K8400.
and thanks for your help by the way
cheers jan[/quote]
manuals.velleman.eu/article.php?id=31
At the end
oh ok, i see… but this isn’t mentioned on the german version of the manual
so i tried Firmware 1.4 and did “Restore failsave” and “Store memory”, I unplugged everything, plugged in the 230V power and i still get MAXTEMP error
wat kan ik nu nog verder doen?
[quote=“rj1”]wat kan ik nu nog verder doen?[/quote]Sit and pray? 
More seriously, no temperature is shown on your display (you should get the room temperature for head 1 -reading like 23/0°).
You should re-check the thermistor. To test it, unplug it from head 1 and plug it in the 2nd head therm terminal on the controller board. The temperature should now show on the left temperature display.
now i’m really scared
i did as you sad and i still get only zeros.
i also checked the connection from the hotend sensor screws to the mainboard pins and i have connection.
defective mainboard?
[quote=“rj1”]defective mainboard?[/quote]It seems highly unlikely both therm outputs are fried.
[quote=“rj1”] I fixed the wrong connected wires[/quote] What did you connect wrongly and how?
while assembling, i did the cables of the heater and of the sensor wrong.
So i connected the heater cables in the 2 middle screws, where normally the sensor cables should have been.
but then i read about it in the forum and i fixed it.
that’s why i thought that maybe the sensor is already damaged and that’s why i bought a new one, but still the same result.
do you need more pictures or anything else?
To check if the Therm input is functioning properly, you can remove the plug of the thermistor and connect a 100k resistor or potentiometer to this input on the controller board. With 100K you should read a temperature about 20°. With a potentiometer you can see if the temperature changes when you turn it.
You can also disconnect the thermistor (2 middle screws on the print head)
Check the resistance at room temp you should read around 100K ohms.
1.) I get 103kOhm from Thermistor
2.) I have wired connection from the 2 middle screws on the print head to the mainboard
3.) I installed new Firmware 1.4
Still I get the MAXTEMP Error I think everything else seams working, since I can do autohome with no problem.
For testing: Can I use the thermistor on the “bed-therm” connector?
Or can I install the dual head firmware and connect everything on the leftside of the print head?
thanks again to all of you guys
jan
[quote=“rj1”]Can I use the thermistor on the “bed-therm” connector?[/quote]You can : a temperature should show on the second line of the display. Or you can plug it on the H2-Therm output (no need to install the dual head firmware to get a display).
I tried 2nd therm and also the bed therm and I get still zeros on the LCD.
…this is really frustrating
Did you try to connect a 100K resistor to one of the Therm inputs ans see if you get a reading?
