M16 tv box

[bumerc]

Did you set the baud rate „115200“ correctly?

[Alessio47]

Did you set the baud rate „115200“ correctly?

Yes all set as guide

[bumerc]

Check if GND is ok, use another location for GND. It may be that TX and RX are placed elsewhere. You have to test this.
Make sure there is sufficient contact with the cable, check if these pins are not provided with a coat of varnish.

[darkholokaust]

i made some tests, referring to this image
https://ibb.co/9GjH6Xy

- left pin is grounded and do not produce voltage
- right pin is not grounded or behind a capacitor, it produces 3,42v constantly and when the power turns off, it decrease voltage slowy

so maybe left pin si GND and right pin is Vcc or not uart pins...

[bumerc]

Look for the datasheet for S905X/W and do a PCB-Tracing. I can not help you here because I do not have this device. One thing we can do without uart, we can short-circuit the emmc pins and try to find out with which bootloader your device can start. For this you have to prepare an mSD with CoreElec or LibreElec. Then we install the uboot from the 0 sector on the same mSD card and try to boot from this mSD.

[darkholokaust]

Referring to this guide
https://forum.libreelec.tv/thread/9319- ... 905-s905x/
i downloaded the Amlogic S905/S905D/S905W/S905X build without suffix and then overwrite the device tree with the "gxl_p212_2g.dtb" from libreelec repo.
The device started libreelec from mSD (without nand) and worked well..

but i think i missed the point with the bootloader, right?

[bumerc]

Referring to this guide
https://forum.libreelec.tv/thread/9319- ... 905-s905x/
i downloaded the Amlogic S905/S905D/S905W/S905X build without suffix and then overwrite the device tree with the "gxl_p212_2g.dtb" from libreelec repo.
The device started libreelec from mSD (without nand) and worked well..

but i think i missed the point with the bootloader, right?

Ok, open the ssh terminal and enter this command:

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fw_printenv aml_dt

post the output

[darkholokaust]

aml_dt=gxl_p214_2g
O_o
custom board, isn't it??

[bumerc]

aml_dt=gxl_p214_2g
O_o
custom board, isn't it??

Yes.

I suspect that in your stock uboot the dtb selection cycle was defined according to the hwid or something similar. This is apparently the reason why you get disconnected during the installation. I will compile an uboot version, which you have to install on the mSD from the 0 sector, as already mentioned. Instructions for this, as well as the instructions with short-circuiting of the pins will follow.
If you can then boot to the LE, then we can safely write the new uboot to the internal bootloader partition of the eMMC memory.

[bumerc]

In the meantime you could do a backup of the stock bootloader. To do this, please boot to the LE and execute the following commands:

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mount -o rw,remount /flash

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dd if=/dev/bootloader skip=1 conv=sync,noerror | gzip > /flash/u-boot_orig.bin.gz

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mount -o remount,ro /flash

The BL-Backup can now be found in the root directory (/ flash) on the mSD card.