More detective work on USB C cable fault:
1. The short cable (supplied with Samsung T5 + T7 SSD drives) I have that works with MEGX unit is a thunderbolt cable.
2. I have tried turning the USB C connectors around by 180 degrees, all 4 possible combinations - no difference, no green light.
3. I tried another UGREEN USB C charging cable (cable described as for charging only) -> this supplies power to MEGX (green light on), but app does not detect MEGX unit, no editing of settings possible.
4. I used a Belkin USB C Thunderbolt 3 cable which has been working faultlessly with my UAD x6 interface for several years. No green light on MEGX, no unit detected by app.
While researching on internet I found this on a forum:
-----------------------
This situation is a total and complete mess. Here is my understanding...someone else can chime in to build upon or correct me as you practically need an advanced degree in USB these days to understand what the hell is going on.
To get the 10 Gbps in your situation, you need one that is a USB-C-->USB-C cable supporting the USB 3.2 Gen 2 protocol, formerly known as USB 3.1 Gen 2, also informally known as USB SuperSpeed+ and also sometimes called USB 10 Gbps. In terms of availability, there are tons of braided cables but not many that are certified. I tend to prefer certified because we've seen seedy cables do a helluva lot of damage to devices and I stick to a few makers that tend to certify their products consistently. Here is an Anker product, for example, which will support 10 Gbps transfer speeds, and is certified. It also happens to support 100 watt charging so you could also use it as a charge cable. It is a very robust cable and it is thick, but not braided.
Amazon Basics has a lot of high-quality and certified USB-C cables...this braided USB-C cable is built to USB 3.2 gen 2 spec, braided, but not certified. I would imagine it is a very good cable though. Unlike the Anker, it is not something you would want to use to charge a MBP, but it would work fine to power a hard drive.
Finally, passive USB-C-compatible Thunderbolt 3 cables will work as well, although you may have inconsistent results with achieving the 10 Gbps on longer passive TB3 cables (the USB 3.2 gen 2 spec technically maxes at 3.3 feet). I am using this 6.6 foot Thunderbolt 3 cable to power a 4K display--users seem to get consistent 10 Gbps from both the 6 and 3 foot versions and I have gotten 10 Gbps from it. (You can NOT use an active TB3 cable though.)
--------------------------
This Anker "Gen2" cable from Amazon might work. But I am loathed to waste £18 on another dud cable....
https://www.amazon.co.uk/Anker-Powe...nd+more+type-c+devices/laptops,aps,130&sr=8-6
Any RJM forum members out there who are successfully using 3 - 6 ft USB C cable to connect an iPad to MEGX unit for app editing, please let me know.