Smoothieboard prevents Raspberry Pi booting

I'm trying to run my smoothieboard from a rpi 3, with Octoprint. It all runs just fine if I boot the pi first, then connect the smoothieboard via usb. If I try to boot the pi with smoothieboard already connected, the boot process crashes and the pi sits there doing nothing. After the crash disconnecting the smoothieboard results in a message that a USB device has been unplugged, but nothing else happens. I can't tell exactly what the causes the crash as there is screeds of text flashing past, and attempts to log the boot messages have failed ( using journalctl), probably because the file system never gets started so the logs are not stored. If I had to guess I'd say its probably happening when smoothie enumerates the SD card as a mass storage device.

And to preempt any power supply questions: yes everything is powered with its own connection to the standby 5V of an ATX PSU, which can supply about 5A - plenty to run everything.

Has anyone else encountered this issue?

Is this a real smoothieboard or some bs clone from china eg mks?

I also would have guessed power... a large drain on the usb port.

have you got a usb cable that doesnt have the +5v line, ie just has + and - data and gnd (or can you make one to try) to go between Pi and smoothie

how long is your usb cable?

Edited 1 time(s). Last edit at 11/04/2017 03:42AM by Dust.

No, its a real smoothie board. X3, but I added two extra motor drives. I got dicked by some a-hole on Ebay - posted a pic of the X5, and send me an X3. At least I only paid the X3 price.

USB cable is 0.5m, the shortest one I could get. And as I said, everything has its own wires back to the 5V supply. I don't think this is a supply issue.

So I restarted from scratch, building a new OS image for the Pi, based off the Octopi image, adding TouchUI as I did before. Only this time it all works. Perhaps the difference is that I had the smoothieboard plugged in the whole time while I was setting everything up ( and boot testing ) so maybe something secret got set up that wasn't there before. I guess it will remain a mystery because I don't have the skills to debug Linux errors.

On to the new issue ...