New M.2 extender board pinouts reversed

@RADXA in none of quite many ordered m2 boards there was not longer cable, I got 2 of them, same lenght, I only assume they are same and second is now simply for a backup, however, a longer one would be much better, not that I care about SD, but I would care about placing it as far as possible from cpu heatsink where I wouldnt have troubles to access other parts of device.

reichelt as your partner is btw somebody I will not order anything anymore from.

I have done exactly the same I think its a combination as they are only 3mm depth and may be pressured by thread that screws in and also its own torsion.

I actually think it would be better if the m.2 went over the heatsink and the ribbon was same side connections as the loop that masks the SD reader is at times a complete pain in the ass.
I am not going to build it up next time the ‘Radxa’ way but have it on its own posts by the side of the Pi44b board.

I aim to put it on top of the heat sink and wondering how many pin is that ribbon cable as going to see if I can source a same sided one to allow the above.

Its AWM 20624 80C 60V VW-1 but how many pins is it as my eyes have been straining to count :slight_smile:

@stuartiannaylor if you start screwing on one, it might affect the others, if you screw after it is assembled, you could put to much pressure on some of them (or even break the board etc…). Due to the fact that eMMC card is a little bit higher and m2 part cant be properly place. This is the reason why I did not put to much pressure on it.

I did not replace it (does not really affect a lot on colling) for now.

As for SD card accessable or not, I already suggested to use, with simple tools like this it is very easy to place SD card into the slot without a danger to break something:

Lols no thanks @cevap on that one.

Suppose you don’t know the pin count of that ribbon cable do you?
I think its 38

Hold on there now, Partner.
I just received my replacement RP4B yesterday and the single sided FPC cable doesn’t work at all. It looks as if the M.2 connector is double sided, but apparently not.

Just to recap, I fried my RP4B while connecting the new M.2 extender board. So, I never had a chance to actually see it working.

But, I still preferred having the M.2 extender board with the SSD facing away from the heatsink. So, I tried the single-sided FPC cable with the board upside down, so that the pinouts would be reversed. But, the SSD wasn’t recognized at all.

So, I was forced to try the new FPC cable with contacts on opposite sides (both ends facing the PCB) and voila. The SSD was recognized.

So, there’s no way around having the SSD facing the heatsink, if the M.2 board is mounted on it.

The good thing is that the new FPC cables are long enough to allow something to be placed in between to shield the SSD from the heat sink’s

Unfortunately, that doesn’t work for me, because everything fits snuggly inside a case. But, I swapped some standoffs to maximize separation and the cooling fans appear to be doing their jobs. Need to do some temp tests to optimize airflow and minimize fan noise.

Hope this helps.:sunglasses:

Yeah to go on top of the heatsink the board is actually reversed hence why I need a different cable to achieve it.
Or I want an old rev board as absolutely hate how it is.
Anyone want to swap a old rev board for new?

I prefer the M.2 extension board mounted onto the heatsink. Perhaps I was the first to configure it that way. You are the only other I’ve noticed on the forum.

The existing FPC cables will do the job. But, you might need to tap the holes out on the heat sink. I suggested that Radxa tap them all the way through, but don’t know whether that was implemented.

Yeah, you’re right about the M2.5 threads being too short on the provided standoffs. Their 10mm long threads only allow a few threads to bite into the heatsink. So, people are tightening them too much and stripping things out.

I use the screws as an adjustment for the M.2 shim spacing from the RPi4B board. Need to hold the heatsink in place while making sure there are ~3 treads showing between the shim and SBC, then thread the screws into the heatsink. But only snug them to the SBC w/o overtightening. Otherwise the RPi4B board starts bending. It’s a very fiddly matter, IMHO.

That’s why I suggested that nylon washers be used to maintain separation.

I purchased 12 mm long panheads to do the job. Also made the suggestion that Radxa use longer screws.

Yeah the heatsink I have is tapped all the way through but like you say doing so reverses the pins.

I can get 15-25mm pillars and also put a 12v fan there and have my sata ports on top and a Micro Sd that doesn’t need tweezers and a lot of patience and fiddling.
With the ribbon cable obscuring and making things hard over time I am going to kill that slot as I will be generating and playing with a lot of images.

The fins on the heatsink look a perfect fit for 2.5mm self tapping screws on a 40mmx10mm 12v fan so I will be sucking air in there and don’t give a damn that the m.2 is on top.

Having a cable across one of the most important ports is for me a high order brain fart, but that is just my opinion but you can tell I really hate it.

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Sounds like a good setup. Looks like you have things under control.
Did you get your SATA drive(s) working on the RPi4B?

Yeah, it doesn’t appear that much forthought has been made regarding how everything needs to fit inside a case. Power on/off switch, for example.:thinking:

Once or twice but the pci-e bus died.

I got a benchmark when I remembered once.

Auto Mode
        Include fsync in write timing
        O_DIRECT feature enabled
        File size set to 81920 kB
        Record Size 4 kB
        Command line used: iozone -a -e -I -i 0 -i 1 -i 2 -s 80M -r 4k
        Output is in kBytes/sec
        Time Resolution = 0.000001 seconds.
        Processor cache size set to 1024 kBytes.
        Processor cache line size set to 32 bytes.
        File stride size set to 17 * record size.
                                                              random    random     bkwd    record    stride
              kB  reclen    write  rewrite    read    reread    read     write     read   rewrite      read   fwrite frewrite    fread  freread
           81920       4    28607    34861    39915    40103    16139    30980

Think I just posted that somewhere else by accident.
The ASM1061 chipset is a bit mweh but the 2 port was a lot cheaper just for a trial, but now wondering was I just unlucky as pretty sure its just a 1 watt device or did I kill the pcie bridge?

Wish I could help with that.
I’m a lot better with mechanical stuff than Linux. :wink:

Its either timing or that pcie bridge is positively deceased and has gone the way of the Norwegian blue.

I have another rockpi4b on its way from reichelt elektronik and will be paying far more attention to the assembly of this one :cry:

@jack suppose there isn’t an old ver m.2 extender I can buy is there?

Bummer. Does the Rock Pi still work, otherwise?
You can have my old M.2 extender! But, I’m not sure why you want one? Are you trying to get the SSD on the opposite side of the extender board from the heat sink?

Yeah just no matter what I do with images kernel versions from being intermittent the pci-e bridge seems to of left the house.
Uboot the lot tried all and various combinations.

I thought the old extender had the pins reversed so if I flip it over ontop of the heatsink the pins should be correct.
So you might want to keep yours and get a new heat sink, if I am envisaging it correctly.

Actually, the old M.2 extender board is too long for the case. But, I have everything reassembled and working, for now.

Yes, you are correct about reversing the pinouts by flipping the extender board, but you will still need to use the new double sided FPC cable, so that the contacts face the boards on each end.

Yeah its a real pain in the arse but the ribbon I have is same side 10cm that will hopefully twist and essentially be like the new double but with the pins reversed… ? ! lols so I think.
Prob too short now I think of it.
Dunno but how it is at the moment with a relatively short 60mm ribbon right across the sd reader slot is just mightily stinky to me.

LOL! You got me thinking about flipping the extender board and I really preferred that config. So, I took everything apart and flipped the new board but used old single sided 40mm FPC cable. (again)
Now the RPi4B won’t boot. It stops when the TV screen goes black (when HDMI drivers load?). Correction. It just took a little longer to get to the desktop.

If you have single sided FPC cables, then you must have received the original M.2 extender board. It is 100mm long and rectangular (w/no side cutbacks for GPIO access).

You can not do that as the pins are reversed hermit! That is why I have to give the ribbon a twist!

Oh feck man! Fingers crossed and put it back quick.

As you say the new ribbon has bare connections opposite sides but that will not reverse the pin order but just make it so it seats correctly pcb facing.

We’re ok. But, I need to check to ensure that the SSD is mountable, etc.
If you turn the board upside down, you are reversing the pin order, so the opposite FPC cable is required.

Back in a few.

Hermit please don’t as the cable does not reverse the order of the pins, only a 180’ twist in the cable will do that.
Only thing that changes is the face it seats on, unless that is an extremely cunning ribbon cable. :slight_smile:
PS dunno why I tried to count its .5mm pitch and 20mm doh so guessing 40pin!

I might of caught the first 38pin order in time and cancelled but I have ordered 40pin type A same side that I will twist 180 degrees and that will allow be to fit the board over the heatsink and also the twist will make the it like a type B oppisite side so its seats correctly.

Then I actually get a heatsink above the cpu and room to fit a fan via the heat sink fins, yeah I am taller than before but actually I have access to sd and camera and display slots.