Device HW status or boot system from SD card?

[Kentril]

Hello, I flashed my MXIII K4 with some firmware. But sometimes it's working perfectly sometimes I got many error messages about google play stopped etc. Sometimes I have problem even boot and only factory reset works. So now it's the question if HW is correct, or only SD card? Exist some tools how to check it? Unfortunatelly I lost the factory image.
Is there any instruction how to boot system from SD card? Not flash firmware but how to create SD card bootable with working system? Than I can check if the HW memory is ok.

Thank you

Jiri

[trotter]

You need a modified uboot to boot from sd. So your still stuck with needing to flash the device.

[Kentril]

I can flash the device, Is there any instructions how to create bootalbe SD card and uboot modification? Thanks

[trotter]

I don't know the unit my self, it just seemed like you was aiming for sd card boot due to not being able to flash it. You say HW problems and booting from SD is not going to fix that.
Chances are it's just really bad rom or a poorly built unit. So you mite as well try to flash a new rom/firmware.

[Kentril]

Ok, I did some tests. I was able to boot LibreElec, but the same, after few restarts and settings it hangs. Always during cleaning video library. So I suppose the memory is corrupted. Is there any instructions hwo to make dual boot? From SD card or USB? Thank for any advice.