Hey, I’ve had some Holybro SiK radios sitting around for a year or so that were formerly working. I’ve tried 4 of them under Windows 10 (running on Bootcamp, also native on an Intel NUC and native on an ASUS workstation and the radios aren’t recognised or enumerated in device manager. The radios also aren’t found under Mac OS X. I’ve done all the usual stuff - download the latest MP and install it, install the drivers, tried the current and older CP102x drivers (and the old ones) as well as swap cables and as mentioned tried 3 different computers. I note the radios communicate with each other (nice flashing lights) they simply aren’t recognised by any host computers. I suspect a windows update has taken place that has broken it, but apart from that I’m at a loss. Additional: Under Mac OS X a CP210x based USB to TTL serial converter works - which would likely communicate with the TTL port on the radios, Any thoughts? Cheers.
Do they use an FTDI chipset? That driver is pretty ubiquitous and easy to install.
Hi Yuri, Thanks for replying. They are Holybro radios which used to work. After sitting unused for about a year they aren’t enumerating on the USB bus. Under Linux an lsusb doesn’t show them and under windows they don’t show up as anything in device manager. They should appear on the bus before worrying about a driver. The perplexing thing is that they all worked last year, and after sitting some 5 of them now don’t. I’ve tested some that have been connected to an Orange Cube and they are the same too. I would be astonished if the whole lot have failed. I can’t see what the chips are as the writing on the has been removed by Holybro. Cheers, David.
Try a different USB cable?
sounds like what happens when you use a charging-only usb cable.
I tried three different cables but no luck, but as I write this check out what happened below in relation to Dale’s comment! 
Hi Dale, Spot on! I had tried 3 cables and not realised there were such animals as charge only USB cables. I grabbed a cable from an Orange Cube and et voila! off it went. Thanks for your very helpful and informative reply! Cheers, David.
I have a charge only cable on my bench that occasionally bites me that way, hence my reply to try another cable.
I should just throw that other one away…it’s near useless anyway!