unable to boot from SDCard

[Charles Tarkowski]

have installed eMMC 32 GB and tried with Debian, all OK, start, SSH via Putty, nand-sata-install, boot without SDCard, all fine.
then i understand, that it is 64-Bit and wine32 do not function in this enviroment, what i need, without this = dead Piece of Hardware for me.
So finding Ubuntu-Version (Bionic with 32 Bit)  github.com_bionic-minimal-rockpro64-0.8.3-1141-armhf.img, tried it and
Hurra, it works, with wine32, x2go, xfce, all I want...(alll on SDCard)
Now beeing unfearful, and try to transfer, or make it new with the eMMC, put the image on /tmp and use
dd Cmd, and now all is gone,
i think i had to delete the Debian-System on eMMC, i do not do it,

Now i try to start without eMMC, and some trial of SDCards, with Jumper (north of the intern button)
all combinations, but no more boot is possible,
the LED's at Network-cable are out,

i do not understand the Connection via TTY and serial Connector, i do not have USB Hardware for this,
some other older PC with seriell Connector is perhaps avaiible.

Pleas help me, any suggestions are welcome..
Charles

[dukla2000]

have installed eMMC 32 GB and tried with Debian, all OK, start, SSH via Putty, nand-sata-install, boot without SDCard, all fine.
then i understand, that it is 64-Bit and wine32 do not function in this enviroment, what i need, without this = dead Piece of Hardware for me.
So finding Ubuntu-Version (Bionic with 32 Bit)  github.com_bionic-minimal-rockpro64-0.8.3-1141-armhf.img, tried it and
Hurra, it works, with wine32, x2go, xfce, all I want...(alll on SDCard)
Now beeing unfearful, and try to transfer, or make it new with the eMMC, put the image on /tmp and use
dd Cmd, and now all is gone,
i think i had to delete the Debian-System on eMMC, i do not do it,

Now i try to start without eMMC, and some trial of SDCards, with Jumper (north of the intern button)
all combinations, but no more boot is possible,
the LED's at Network-cable are out,

i do not understand the Connection via TTY and serial Connector, i do not have USB Hardware for this,
some other older PC with seriell Connector is perhaps avaiible.

Pleas help me, any suggestions are welcome..
Charles

OK - I suspect your flashing of the eMMC was bad, but no matter. Your immediate problem is you cannot boot from any SDcard. You do not need TTY/serial connector/USB ...

Just a freshly burned image on an SDcard:
- remove any eMMC
- NO jumper on 16
- Just the SDcard inserted with an HDMI screen to start
then power on. If you get something working on the screen then you can add a keyboard, network etc connections.

Good luck

[Charles Tarkowski]

That exact what i tried, but.. on HDMI on my 4k-Monitor never seen a signal, tho whole time, is it possible, that some Monitors are not function?, the screen become black, but no char's on it. Is it possible, that there is an other component Boot before SDCard?

[dukla2000]

That exact what i tried, but.. on HDMI on my 4k-Monitor never seen a signal, tho whole time, is it possible, that some Monitors are not function?,  the screen become black, but no char's on it. Is it possible, that there is an other component Boot before SDCard?

Conceivably your SPI is corrupt - you could try disabling the SPI while you boot (next entry in the wiki)?

If you are not sure your monitor will work that is a slight concern - I would expect most do though. But equally if you try something like an Armbian image then you should see activity on the on board LEDs as well.

The boot sequence is documented here: conceivably you could try rebuild a bootable eMMC via OTG mode but I think trying to get a bootable SDcard would be my first choice.

[Charles Tarkowski]

Thanks a lot, the solution was:
tried some other images, (monitor is still black) without eMMc, one works,
than reinstall eMMc, every time wants a passwort for root i not remember,
so start with jumper, remove it in 2 sec. and the result is:
start from SDCar and eMMc is visible,
so fdisk /dev/emmc..
delete all partions
and the system is so new like a baby
Hurra