RPi 4 4gb vs 8gb, using micro SD card extender, voltage/amperage difference?

Okey, I have a puzzling question in case somebody somewhere outthere run into the same problem.

I have two Dual SD Card adapters bought from Jaycar that I can put to SD Card and use its switch between A and B whic was bought 4 weeks apart.

The issue is: the 4Gb RPi4 does not like this adapter no matter which slot I put it in. the 8Gb RPi4 never has this problem since day one I came to know this Jaycar product.

Secondly, to my curiousity I attached the micro SD card extension ribbon I bought from here. The 8Gb RPi4 does not have any problem at all. The 4Gb RPi4 does not even read it! It just threw a buncha text of something about the storage inaccessible bla bla bla.

Interestingly, I bought micro SD card PCB extender from here too, it does work on both 8Gb RPi4 or the 4Gb.

At first I thought Jaycar product was faulty until I attached to the 8Gb and it runs happily just like the first one.

By the way, the 4Gb has hifiberry hat attached to it while the 8Gb is plain vanilla.

So, would any one has this experience that can be shared with me to enlighten my curious mind.

Thank you.


Hey Iman,

Yes, that’s a known issue with a few reversion of the Pi, although it’s interesting that it’s working with the Pi 4 8GB.

There’s actually a resistor on the inside of most of these adapters which causes issues with some devices when they try to read from it. They’re mainly used for desktops and 3D printers so that the actual connection doesn’t wear over time as quickly as you leave the extender in place.

If there’s anything else that I can do for you please let me know!

Core Electronics | Support

IT IS interesting… the idea to use an extender is pretty much having the same objective of using it on 3D printer or computer.

I forgot to mention another specific point, the Jaycar extender in fact works with Hifiberry O/S in the 4Gb RPi 4 in either slot It always work with PCB extender but then it always does not work with the ribbon SD card extender. Weird, isn’t it.

Anyway, it’s good to know. By the way the 8GB RPi is still happy with it, I wonder if another batches of the 8Gb will behave the same way.


Hey Iman,

I suspect that they will. The Pi 4 8 GB are all a new revision of the board, whereas some of the older Pi (the Pi 4 in particular) had multiple versions. However, this issue is a little intermittent between devices I’ve found, it’s quite difficult to determine the exact cause.

Core Electronics | Support

in my op it is a power problem whereby voltage drops in the extender cable length specially at those minute cables where current really counts in a big way also it could have a lot to do with baud rates.
if that is a factor here concerning the cable.

the usd adapter may not play up in a different rpi board due to component tolerances at time of production specially capacitors having or becoming a factor of quality.

it could be an issue.???

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Hey Brian,

That could potentially be the case, but it’s hard to determine without being able to do a series of further tests to confirm it. Make sure to let us know if you find any further information on it. It’d be very useful for further users to refer back to this conversation if we’re able to solve it.

Core Electronics | Support

its simple to me its a power issue…voltage drop specially in d.c circuits most likely adding an electrolytic across the the voltage rail would most likely solve the problem …

as far as usd speeds are concerned …i think that the cable length is everything…a.c is used in the mains wiring across almost every country as a.c can travel further in long lengths without drop`s whereby d.c. will always have some voltage drop however small it may be …i found that Kingston don’t always allow a dual partition on an usd card…in the past…Kingston cards can flash under “etcher” and verify even then when you put the card into a card reader the boot partition is not even there only a single partition was written to the card …i did not delve to much into this i just went to sandisk cards.

i dont have the said devices so it`s hard for me to conclude the exact problem at hand…