Can't boot from SD card anymore

My board worked for 1 day. Now does not boot anymore.
Am I doing something wrong?

Apart from that, I never got the boot login screen. I use FTDI serial interface and could see boot log just fine, but never got to the first login screen.

Now it hangs at:

RDA8810 Boot_ROM V1.6
HW_CFG: 0286
SW_CFG: 0000
Load EMMC
Open eMMC

Is my board defective?

Thanks

Setting the boot jumper to internal memory gives me this output:

RDA8810 Boot_ROM V1.6
HW_CFG: 0282
SW_CFG: 0000
Load NAND
Nand Init, type = 06 (bus 8bit)
Nand Init Done
Loading Image from NAND … Done
Check Image Magic Error FFFFFFFF
Load NAND Fail
Load SD
Open SD card
mcd_Open
Card is SDHC
Inserted Card is a SD card
mcd_Open Done
Loading image from SD card …Done
Check Image … Done
Run …
Init Clock …
Clock config ver: 1.0
PMU vbuck1 = 9, vbuck3 = 10
setup ddr vtt to 1

… and hangs there.