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macstatic

macrumors 68020
Original poster
Oct 21, 2005
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164
Norway
I've installed a Sonnet Allegro 4-port USB 3.2 PCIe card in my cMP 5.1 running MacOS 10.13, but for some reason my iPad Mini (5th gen/iOS 13.5.1) displays "Not charging" (upper right-hand corner along with the clock, battery status etc.).
Syncing with iTunes on my Mac works fine.

Any idea what is causing this and what I can do about it?
 

macstatic

macrumors 68020
Original poster
Oct 21, 2005
2,024
164
Norway
I hadn't thought about that.
Another concern might be that it's connected via a USB-C to USB-B cable (USB 3.1 certified) which goes into a USB-A (USB 3) front-panel connector (for easy access from my desk). This should give me USB 3.1 with a standard USB-A connector, and that's where the USB cable for my iPad goes.
I've previously used the same front-panel connector with a USB-A to USB-B connector which plugged into one of the rear USB connectors of my cMP and it's charged the iPad fine, but perhaps the PCIe is different in that it supplies less power than the cMP's own USB 2.0 ports.
 

nicho

macrumors 601
Feb 15, 2008
4,250
3,250
I hadn't thought about that.
Another concern might be that it's connected via a USB-C to USB-B cable (USB 3.1 certified) which goes into a USB-A (USB 3) front-panel connector (for easy access from my desk). This should give me USB 3.1 with a standard USB-A connector, and that's where the USB cable for my iPad goes.
I've previously used the same front-panel connector with a USB-A to USB-B connector which plugged into one of the rear USB connectors of my cMP and it's charged the iPad fine, but perhaps the PCIe is different in that it supplies less power than the cMP's own USB 2.0 ports.

Could be the new cable at fault. This one for example:


only delivers 2.5W.
 

macstatic

macrumors 68020
Original poster
Oct 21, 2005
2,024
164
Norway
I plugged a cellphone into my front-panel USB connector and it started charging (without any error message) so I assume this means that the connection itself is OK, but as Krakman pointed out earlier, my iPad may require more power than the USB-3 card can handle.

The USB-C to USB-B cable (USB 3.1) I've used is from Startech. I can't find any info about current limitations on their website. Where was there a mention of 2.5W on that Dell cable link?

It would be interesting to connect a USB-C cable directly to the USB-3 card and see what comes out of it...

PS: I don't know if this is of significance or not, but after fully charging (100%) my iPad Mini I attached it to the USB-3 card and it showed the usual "green battery with lightning" icon. I tried attaching/removing the USB cable several times and it worked the same way every time.
So next I tried draining its battery a bit (by playing a movie a few minutes, until it reached 98% battery) and attached it via the USB cable again, but this time I got the usual "Not charging" message.

So is this typical behaviour of an iPad not receiving enough power from its charger? (on second thought I should probably post this question in one of the forum's iPad sections).
 
Last edited:

nicho

macrumors 601
Feb 15, 2008
4,250
3,250
Where was there a mention of 2.5W on that Dell cable link?

The Dell says it delivers 5V and 500mA (aka 0.5A). Math makes that 2.5W.

Your cable doesn’t mention those details but don’t be surprised if it has similar properties. USB type B devices are usually powered (printers etc) so power would not be a priority.

phones generally require less power than iPads. Everything you’ve mentioned points to the usb card being underpowered and unable to provide enough power to the iPad.
 

macstatic

macrumors 68020
Original poster
Oct 21, 2005
2,024
164
Norway
I plugged a cellphone into my front-panel USB connector and it started charging (without any error message) so I assume this means that the connection itself is OK, but as Krakman pointed out earlier, my iPad may require more power than the USB-3 card can handle.

The USB-C to USB-B cable (USB 3.1) I've used is from Startech. I can't find any info about current limitations on their website. Where was there a mention of 2.5W on that Dell cable link?

It would be interesting to connect a USB-C cable directly to the USB-3 card and see what comes out of it...

(I'm the OP)..... and almost 2 years later I got hold of a USB-C to Lightning cable ;)
Having connected that cable from the PCIe card to the iPad I was able to charge it right away!

So, the problem was the USB-C to USB-B cable. From what I understand, USB-B connectors don't have the required pins for powering, while the USB-C to Lightning cable does.
Problem solved! 👍
 
Last edited:
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