The Big Bang
I had a lapse of concentration when reconnecting my XL_STAR and connected the USB cable to the wrong USB connector.
There are two USB connectors - the right one and the wrong one (for power).
I only came to notice something was wrong when trying to run my program.
In my frantic search to fix this I discovered a new 1.04 revision of the XL_STAR Users Manual (entitled "Developing code for the element14/Freescale XL_STAR board") now which describes this very issue very first few pages and how to avoid it.
Hoping to recover from disaster, I drilled out the PCB hole near C1, checked for the open circuit and powered it up properly.
My XL_STAR sprang back to life. But how wounded? Only time will tell.
I built and downloaded my program and then crossed my fingers. It worked.
It is looking hopeful.