EMMC and EMMC to SD adapter not working

#1

Is there any special trick to make the micro SD to EMMC adapter work because I can not get windows to recognize anything.
I have tried 4 different micro SD adapters now and I get nothing
I am starting to think I got sent defective hardware.

EDIT: ok I tried a really old micro sd to USB 2.0 I had and it worked
but Balena etcher failed at the end of the flash ,the reader or the adapter must have failed.
I could not format the emmc back to the full space obviously, there were a bunch of partitions in disk management so I tired to delete them all but not there are 2 partitions and I can not delete them or merge them and the emmc is only showing 512 kilobytes
how do I fix this?

#2

Mine worked maybe once or twice , tried several SD card adaptors, just use the rkdev flash tool and change partition to eMMC, I have used that to flash img to it

#3

am666…your tip just saved me a whole lot of frustration.
I have been using my Rock 4c+ to burn images for my Rock 5B.
And that had its own problems due to missing fat specific utilities…resolved.
However, I have since put the 4C+ in a case with a lot of screws and fiddly stuff. Using an ancient sd to USB adapter (which could not read the newer higher density sd cards) to access the emmc on the sd card adapter was key.
Many many many thanks