Hi Jim,
You say you’ve tried with “a couple of different power supplies including the recommended Anker one and using a battery pack.” I take it from this that this is a ‘carry on’ (rather than a semi-permanent) install? - In what type of aircraft?
Despite several years now flying with PilotAware, I have only needed to change cables a couple of times (mine is a semi-permanent install), so my personal experience of cable failure is mostly limited to other people’s units. In most cases this has been due to mechanical damage at the microUSB connector end from repeated plugging and unplugging, so I always advise trying to avoid unplugging the microUSB end from the Pi as much as possible. I’ve had a couple of cases where wear at the Raspberry Pi connector has been so bad that this has required replacement of the board.
If you have a look at some of Jeremy Curtis’s recent posts such as...
http://forum.pilotaware.com/index.php/topic,1678.msg18247.html#msg18247(Jeremy makes the excellent Charge 2 and Charge 4 Aviation power supplies so he knows a lot about cables) he comments on the fact that all flexible cables are susceptible to breakage of individual strands of wire within the cable, which will eventually reduce its capacity to transfer power, though your experience definitely seems excessive.
From your ‘post Rosetta’ tests, it certainly seems likely that the cables
are breaking internally, though possibly at the microUSB connector. It would certainly be worth checking the fit of the microUSB socket in your Rosetta and trying to avoid plugging and unplugging at this end - or certainly taking great care when doing so. I would also suggest contacting juicEbitz via their contact form on
https://www.juicebitz.co.uk and see what they have to say about the high level of cable failures you are experiencing. Certainly when I have in the past reported a faulty cable they immediately sent a replacement (do please let us know). It might also be worth trying the 20awg Anker braided cables (available on Amazon) to see if they give longer service. (Edit: or the ones Lee has mentioned in his post while I have been typing).
Please let us know how you get on.
Regards
Peter