Raspberry PI 3B+ stops responding after reboot

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1

Hello,

First of all, thank you for this project. It works like a charm for me, except for the following issue (which might not even be yours actually).
I am curious to know what happened.

In a nutshell:
OctoPi is working flawlessly. After turning off, unpluging the RPI3B+ (pi) from the PSU and reconnecting it, the pi doesn't respond anymore (while connected to the printer). Only the PWR LED is ON, the ACT doesn't even blink once.

How to reproduce the problem:
I followed the installation guide that you can find on the download page of octoprint.org and OctoPi worked flawlessly.

The pi is turned off using the OctoPi web interface, the PSU connector removed from the RPI3. Then, the pi doesn't repond anymore when reconnecting the PSU to the pi. The pi was still connected to the printer Creality CR6-SE (I have read the thread :blue_book: [backpowering]).
This happened with two pi(e?:upside_down_face:)s already.

What did you already try to solve it?
What does the job:

  • Switching to a new pi and reinstalling the microSD card (I haven't tried with the "previous" OS).

What doesn't:

  • Formating/reinstalling the microSD card
  • Using another microSD card (SAMSUNG 8/16GB, SanDisk 8GB, Verbatim 16GB)
  • Trying to boot to re-flash the pi EEPROM (see Raspberry PI forum)
  • Using another PSU/cables

All these methods were tried using a computer screen connected to the HDMI port of the pi

Additional information about your setup

OctoPrint/Pi:

  • The OS has been installed on the microSD with the Raspberry Pi Imager v1.7.2 on Windows10
  • OctoPrint version: 1.7.3
  • OctoPi version: 0.18.0

Printer:

  • printer: Creality CR6-SE
  • firmware: stock

It seems that turning the power off on the raspberry PI while connected to the printer was not a good idea at all, but I am struggling to understand why it fried the microcomputer like this.
I am wondering if there is a method to prevent this from happening in the future and if there is another method to repair the raspberry pi.

Thank you for your time and your help,
Best,
B

Also, I got a third pi out of service (which was actually the first one): I turned off the printer while the pi was still connected to it. Since this moment, the pi was not accessible online (with the OctoPi interface) anymore. I'm just realising now that it actually "responds" the same as explained here.

2

Do you shutdown the Pi before pulling the power? If you just cut power then the SD card could be corrupting.

3

yep this is the first step I have done:

4

Creality printers (or more specifically, the controller board in them) do not act rationally when the USB cable has the +5V connected. The most common symptom is that the printer LCD remains powered by the +5V from the RPi when the printer is turned off.

The current draw of the controller board is high enough that this often causes power problems on the RPi. The solution is to put tape on the +5V pin on the USB A connector (or other wise break the connection).

Conversely, when the printer is turned on, +5V (or more) may appear on the USB cable and the RPi may not like that very much and it may cause harm to the USB circuitry on the RPi. The solution is to put tape on the +5V pin on the USB A connector (or otherwise break the connection).

Now that the printer's power and the RPi's power are separated (by adding tape). You can turn the printer on and off or shutdown the RPi and turn it off independently.

I leave my RPi powered on most of the time. It doesn't draw much power and its convenient to be able to communicate with it without the printer. I even have a smart plug on my printer so I can turn it on and off with an OctoPrint plugin.

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5

Sorry, I must have missed that when reading it.

If it is struggling to boot, connecting a HDMI screen is useful as boot errors should be shown there if it is crashing.

6

hehe, thank you Charlie, I've done that as well already :wink:

7

Thank you Morgan. It's a smart choice.
I'll then remove the +5V connection that currently exists between the two entities.

I hope I can still find a fix for the RPI that are currently out of service!

8

I've been using these USB power blockers to prevent my Pi from sending power to the Ender 3. You can accomplish the same thing with electrical tape over two of the leads in the USB plug (do a Google search for photos).

https://www.amazon.com/gp/product/B094FYL9QT/

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