Good News:
it turned out, that the USB port I used was the Problem.
After trying all of my micro-USB cables, I thougt: "okay let´s just try a diffrent USB-port!".

Now the diag-LED is blinking as it shoud!

Thanks for your help so far!

What should I do now, in order not to "break" it again?

@bearer said in "DCS is not started" error - Duet3:

just out of curiosity, was this with the same usb cable you succeeded with in the end?

no, I belive that was a different cable and the "non working USB-port".

(It worked when I used a different USB - port. At first I used the port on the backside of my Keyboard (I use a "Corsair K70 LUX"), that woked with the duet2, but not with the 3! In the end, I plugged the duet directly into the front of my PC and using the included cable from the duet2!)

@bearer said in "DCS is not started" error - Duet3:

when you get a new duet with a pre 3.0 it will break compatibility with dsf without either manually updating to 3.0 before using apt upgrade, or use bossa or sam-ba after apt upgrades to 3.1.1. shame this isn't highlighted better.
too bad about the series of unfortunate events sort of speak, but glad you got it sorted in the end

I didn´t kwon that unfortunately...
But now everything works, and I have some more knowlage for next time

Thanks again for your help!

Everything on the softwareside works perfectly now!

Thanks everyone for your help!

I don´t know what I originaly did... I messed something up, and than nothing worked anymore !

I´ll make my configs now.

Good News:
it turned out, that the USB port I used was the Problem.
After trying all of my micro-USB cables, I thougt: "okay let´s just try a diffrent USB-port!".

Now the diag-LED is blinking as it shoud!

Thanks for your help so far!

What should I do now, in order not to "break" it again?

I took it out now. It didn´t change much.
(and I´m still swapping cable around )

@T3P3Tony said in "DCS is not started" error - Duet3:

It should not now show up as a BOSSA programming port.

But it does, why´s that?

the board is on my desk.
Nothing except for the USB-cable, and the SD card is plugged in.

The cable i´m currently using was included with my duet 2...
I´ll try all of my other cables, maybe one of them works...

I just tried many different things, including different cables, but I just can´t get a conection to the board.. I mean, BOSSA and SAM-BA show the serial port, but I get the same error massages as befor (the pictures further up).

Is there something im just forgetting about?

The Diag-LED is still always dimm. I tried with and without the SD card, Plugged into the PC or a Phonecharger... no change

@bearer said in "DCS is not started" error - Duet3:

wget https://pastebin.com/raw/Wa1kYf3G -O - | tr -d "\r" | bash

I get an Error with that command:

pi@duet3:~ $ wget https://pastebin.com/raw/Wa1kYf3G -O - | tr -d "\r" | bash
--2020-08-17 14:28:50--  https://pastebin.com/raw/Wa1kYf3G
Resolving pastebin.com (pastebin.com)... 104.23.99.190, 104.23.98.190, 2606:4700                               :10::6817:62be, ...
Connecting to pastebin.com (pastebin.com)|104.23.99.190|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: unspecified [text/plain]
Saving to: ‘STDOUT’

-                       [ <=>                ]     897  --.-KB/s    in 0s

2020-08-17 14:28:53 (3.53 MB/s) - written to stdout [897]

Cloning into '/home/pi/BOSSA'...
fatal: unable to access 'https://github.com/shumatech/BOSSA/': Could not resolve                                host: github.com
bash: line 26: cd: /home/pi/BOSSA: No such file or directory
make: *** No rule to make target 'bossac'.  Stop.
/dev/ttyACM0 not found******

I didn´t use version 3.0 first...
How can I install it now?

wich board do I have to use in "SAM-BA" for the duet3 ?

This is what I get if I use the "Board for the duet 2":

And this is the Problem in BOSSA: