No response from G28 on Rostock Max

[thingevery]

I'm stuck and I'm hoping somebody can help me out. I can connect to the printer in Repetier Host and the commands M119 and M115 are working correctly, but when I enter a G28, nothing happens. No error and no movement from the machine. The power supply is plugged in and turned on.

Here's what I've done so far:

After assembling the Rostock Max and wiring everything up, I plugged it in to my Mac and started up the Arduino IDE. I selected 'Arduino Mega 2560 or Mega ADK' and '/dev/tty.usbmodem1d11' and then uploaded the Blink example (which worked). Then I uploaded johnolly99's 'Marlin for Rostock Max' firmware and launched Repetier Host. I was able to connect and M119 & M115 work, but G28 doesn't. It just says '1 commands waiting'.

So then I went through that whole process again in Ubuntu, with the same results.

Anyone have any ideas? Did I miss a step?

[Polygonhell]

First possible issue is the hotend thermistor needs to be connected and returning a reasonable temperature, what is it reading, if it's not connected or not reading a reasonable temperature the firmware goes into failsafe mode and pretty much nothing works, the TTY window usually has a message about this, but you'll need to enable all the TTY channels in repetier host.

If it's not that, the next question is does your hotend heat up if you set the temperature to say 40 degrees?
It could be a couple of things, if it does nothing the likely culprit is a lack of power, do you have 12V going to all 3 sets of power pins on the RAMBO, and can you verify the voltage with a meter on the screws on the connector.
If you have power there and the hot end works the most likely issue is the fuse on the RAMBO board, there are two tiny fuses, the one for the steppers is just below the power connector, with a meter you should ground one probe and test for voltage on both sides of the fuse to verify it's intact.

Problem could also be the stepper wiring, but that usually does something.
NOTE the stepper drivers are really sensitive to plugging or unplugging the motor connectors with power applied either 12V or the 5V from the USB port, it can permanently damage them, but it seems unlikely you've blown all 4.

[barnett]

If you're not getting the error about the failsafe mode (hot end thermistor wiring), it could have to do with the power supply. Without power, it would act as you describe and also not heat up.

[thingevery]

Awesome, thanks for the tips! I wasn't providing power to all 3 sets of pins. The PDF instructions (v1_7, step 22.4) says to cut off the six pin connector and use those wires, but then it says to put three wires together on each of the first two pins, so I used that whole set of wires just for the heated bed and then spaced out and left the other four pins open.

Now it's working! All axis went up, and the hot end warmed up.

I really appreciate the help. Time to celebrate - and then calibrate.