Dell Venue 11 Pro (5130) Will Not Charge

We purchased a Venue 11 Pro in July 2014.  Starting about 6 months later, the following pattern would occur:

1) At some point the tablet will stop charging properly

2) We'll switch to different outlets, jiggle the USB cord, etc. and it'll charge fine a couple of times

3) That'll stop working and we'll replace the USB cord

4) The tablet will charge properly for fewer times than before

5) See step 1.

In the current iteration, it charged properly twice and then stopped. A new USB cord *does not solve the problem*.  The tablet is currently out of charge and inoperable, so updating the BIOS, etc. aren't solutions.