alt Hacker NewsSometimes it's not the cable. Sometimes it's the sodding device. I have some IP60-something speakers for the shower. Write up says USB-C power. Brilliant says I, I've got plenty of good ones I use for charging laptops and other USB-C form factor accepting devices.
Sodding things only charge with their special USB-A to USB-C cable. They're in the bag labeled "cursed usb-c charge cables".
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It's because they are straight up defective. The USB-C spec is pretty clear in that the power pins have 0v until you signal for a voltage. This isn't a failure of USB-C, you should just return defective devices to the OEM.
Thankfully this defect is becoming less common outside of temu junk.
That's because they didn't implement USB C correctly. Maybe it was to save less than a penny on the BOM, maybe it was arrogance ("it works for me! send it!"), or maybe it was something else. Whatever the reason, they didn't do it right.
By standard, USB C provides no power at all unless the device being powered follows the rules. They're easy rules to follow. The minimum viable way of doing it right requires just two tiny resistors inside of the device.
I have a water pump like that, the reason: they have omitted the 5.1k resistors…
you'll never guess what solution i'd suggest for that specific problem...
I do electronics professionally. This is likely because in order to save a bit on BOM costs, the device itself doesn't have the necessary pulldown resistors to signal to turn on VBUS.
USB-A has always-on VBUS while USB-C doesn't. Because the spec allows for always-on VBUS in a USB-A to USB-C cable, some devices just assume that they're always being powered by one of those cables.