I purchased a NanoPI R5C from Amazon Canada in February and it no longer turns on.
I’ve tried with a known good SD Card, or booting directly from eMMC and there are no status LEDs at all. If I leave it for a few hours the chassis does get warm but no status leds or network leds.
It was always used with this high quality Gan charger and cable; it was working fine for a few weeks.
Does it turn on properly after you receive the shipment?
Do you have a 5V type-C power supply? Link the HDMI of the R5C to the display and power it with a 5V power supply, does it show up?
As you said, you tried burning firmware, which firmware did you burn? Can you provide it?
If the SD card didn’t boot successfully, try formatting the SD card after deleting all partitions via DISKGENUIS and burn the firmware for this SD card again.
https://drive.google.com/drive/folders/13bGJovpITmIGYImYYtp7W3Nl97ckJ3Mh?usp=drive_link
By the way , do you have a USB A to A Cable?Refer to this wiki to burn firmware:
https://wiki.friendlyelec.com/wiki/index.php/NanoPi_R5C#Option_3:_Install_OS_via_USB