Radxa A7S compatibility with eMMC module

Cubie Series A7S
1

Hi everyone,

I’m trying to add eMMC storage to my Radxa A7S by reusing an eMMC chip desoldered from an Orange Pi eMMC Module 64 (part number: ISOCOM MEMDN064G, 64GB).

What happened:
After soldering the eMMC chip onto the Radxa A7S, the board completely stopped functioning and was drawing less than 1mA of current! As soon as I desoldered the chip again, the board returned to normal operation and current draw immediately.

My questions:

  1. Is the Orange Pi eMMC Module 64 (ISOCOM MEMDN064G) actually compatible with the Radxa A7S eMMC footprint/interface?
  2. Could the near-zero current draw indicate a short, incorrect pinout alignment, or an incompatible eMMC spec (e.g., voltage, bus width, or timing)?
  3. Are there any specific things I should keep in mind before attempting to resolder — such as voltage levels (1.8V vs 3.3V), bus width configuration, or required pull-up resistors?

Regarding unpopulated components:
The official Radxa A7S documentation mentions that components near the eMMC footprint are not populated by default. However, I couldn’t locate any unpopulated footprints on my board — everything in that area appears to already be populated. Did I miss something, or is it possible the board revision I have ships with those components already placed? I only soldered the eMMC chip itself and did not add any other components.

Any guidance would be greatly appreciated. Thanks!

2

I read that Orange Pi eMMC is not compatible with Radxa boards:

Plugging an Orange Pi eMMC into the Q6A causes a short circuit on the UFS power supply lines, which triggers the immediate shutdown protection you are seeing.

Source: Windows on Radxa Dragon Q6A - #65 by nighthawk

So it is likely that it is not compatible with Radxa A7S.
However there might be workaround.

3

I confirm that the Isocom FEMDNN064G worked flawlessly with the Radxa A7S, after multiple reball attempts and experimenting with (and later reverting) kernel parameters.

4

The eMMC module doesn’t work due to grounding on reserved pins, but the chip itself is compatible with Radxa SBCs.

1 Like
5

Hello board friends, it possible to sharing a short overview of the compatible eMMC chips? Perhaps there a list by manufacturer, capacity (256 GB, 128 GB), data-speed and a concrete grid pitch for the solder mask?