[Power] Auria sample, zero output, failure analysis

[James Cameron]

One of the panels that I received has zero output.  It had been used
by an adult (me!) for a couple of days with an OLPC XO-1.5.

I began by slicing off the nylon hem along the long non-folding edge
using sheet metal shears, and inspected the cabling.  Nothing seemed
wrong.

Then I sliced off the remaining nylon hem to get a microscope into the
termination points.  They are covered with a clear material, like a
hot glue.  Nothing seemed wrong.

Then I used a voltage meter and probed.

One of the terminations of the short interpanel jumper was
intermittent.  Applying light finger pressure over the termination
area made it conduct.

I flexed the jumper slightly, and felt it was not anchored.  I gave a
very light axial pull on the jumper, and it came out from under the
clear material.

The jumper cable is much stiffer than the long cable, because it has a
greater diameter.

In my opinion, this failure could have been contributed to by shipping
or handling; especially folding and unfolding.  The larger diameter
jumper cable and the short distance it travels makes it the most
likely point of failure.  I don't think there is enough clear material
over the contact area to prevent a cable of this diameter and length
from moving relative to the panel.

Photographs at
http://dev.laptop.org/~quozl/2012-07-12-auria-sample-failure-analysis/

-- 
James Cameron
http://quozl.linux.org.au/