Cant get my Nozzle to heat up

Im building the Edge 3D v1.0(http://www.instructables.com/id/Edge-3D-Printer-an-affordable-open-source-3D-print/) and got all the parts gathered.
I tried every single piece and at first i got my nozzle to heat up once. But now it wont.
It doesnt show any errors, i connected it over USB and looked at the serial monitor. But here too, it doesnt give me any errors.
I got a LCD for controlling the printer.

Please Help me, i already looked at all the source code.

JakobSachs

Do you have a thermistor connected to the controller? Is the thermistor OK?
Is the heat element OK? Can you read a resistance with a multimeter?
-Olaf

Yes the thermistor works and gives me correct temperatures.
Which resistance do you mean, thermistor or hot end ?

resistance of the hot end heater element, ie has it blown

OK i messured both resistance and got a value out of it.
So what could it be ?

Dodgy hot end connector at the electronics end perhaps? Also check for cracked wires by wiggling.
What value did you get for hot end resistance? it should be low, under 10 ohms I'd imagine. If your meter is auto-ranging the it might have jumped up to the mega ohms range without you noticing and you were, in fact, measuring your skin resistance.

Cheers,
Robin.

I soldered the cabel ends so they dont shortcut eachother. They are both cliped into a screw terminal, which seems pretty solid. For my Hot-End i measured round aabout 60 Ohms.
The cabels are wrapped with plastic fabric and are quite resistant to bending,

A little update, i got it to heat up by connnecting the heat end to heat 2. But it doesnt stop at maxtemp(275) and goes up to 300, where i disconnected the power.
Any idea what could cause that?(I got my Motherboard set to EFF(Extruder,fan,fan) because i got no heat bed and only one extruder)

So probably "Heat 2" is being used as a fan, and is on all the time?

Maybe configure the board as EEF, and just use Extruder 2?

The fact that it *does* heat up means that the hardware back as far as the board is good. The problem then is either in the software or the RAMPS board. Check that you're getting 12V across the heater output pins on the board. If not, trace back to find whether the ATMEGA2560 pin is switching or not.

If i measure the Voltage that gets out of the assigned pins, im not getting 12 volts. Do i need to have the Hot end pluged in too or not? Also what do you mean with :" ... the ATMEGA2560 pin ..." , which pin it that? I googled it and dindt get a result.

No, you don't need the hotend plugged in. But NB: By default, Marlin won't turn on a heater output if it doesn't find a corresponding thermistor connected.

You can find the RAMPS schematic at . The "Heaters & Fans" & "Power" sections on the left is what you want.

If you're not getting 12V out, what are you getting? Is there 12V on the supply rails of the RAMPS? NB: there are 2 different 12V supply rails (+12V & +12V2)... one of these supplies one output, the other supplies the other 2, Do LED2, LED3, or LED4 light up when you turn on the output.?

Only relevant once you've verified that you've got good 12V supplies and it's still not working... From the schematic you can see that the pins on the Arduino board for the heater & fan outputs are D8, D9, D10. It's probably easier to access these at R13, R14, R15 on the RAMPS. These should be 0V or 5V.

I dont know why or how, but it works. I was on vacation had no chance to build on it. So as i tried it today it suddenly worked, with the same firmware and the same hardware config as before.
A huge thanks to you all, how helped.