RepRap OMNI M-505 - Hot end is not heating

Hello everybody,

I'm completelly begginer. So excuse me my stupid question.

I finished assembling my 1st RepRap OMNI M-505 3D printer (Prusa i3 clone). It have Reprap Melzi 2.0 1284 P controller.

I try print from SD. But Hot end (Extruder) not heating self, also hot bed not heating self. I try lot of configuration from printer menu, but it not work. Fan and step motors works OK. I try check voltage on printer mainboard on output terminals for extruder and hot bed when "pre-heating" was selected from menu and displayed on display. It's 0 volts. After several minutes is "killed" displayed. I include picture as attachment. Extrudor and hot bed are cool.

Have you any tip for me please? Or is mainboard dead?

Thank you in advice for all tips!

Hubert

Edited 3 time(s). Last edit at 10/29/2015 06:55AM by Hubis.

First thing to check is if the thermistors (temperature sensors) are working and giving the correct temperature at room temperature. Use your hand to warm up the sensor and see if the read out reflects the higher temperature.

Next is to see if the configuration of the firmware is correctly set, if there's an exruder defined and set to the correct board/pin. I don't own a melzi board so I can't help you find the pins on the board. You may be able to locate the mosfets and see if you can measure 4 to 5V on the gate pin. Lookup the datasheets of the mosfets on google to find the correct pins. If it's 0V then the incorrect pin may be set or the gate pin is short circuited to ground through a defective mosfet.

Try connecting the fan if you suspect the hotend and heated bed may be bad.

Same issue for me. I uploaded a video here:
[youtu.be]

I will try the firmware solution. I hope I will understand.

Regards,

Cédric

Hi all
I am new to this and have just finished assembling printer. The display is a series of squares but I can just read .
The nozzle heater just keeps heating and reaches 315c . Is this a thermister problem?
Any advice would be appreciated
Jim

Hello Jim,

"The display is a series of squares but I can just read"
I had this the first time I started the printer. Then after one restart the screen worked. But I guess you already tried that.

For the temperature it may be. It may also be a firmware issue (I also have a temperature issue, high temperature can't be reached, and I am trying to find out how to install the firmware delivered on the sd card).

Regards,

Cédric

Had same problem. The melzi board is bad about to much heat at terminals melting terminals. I soldered directly to board and put in a relay to handle load

My screen shows desired temp of Hot end 240 deg. but it only heats to 10% lower whatever I set, so the print doesn't start as it never reaches the set temperature, I am running repetier and Cura, and it never prints from PC only SD card.