Lots of broken chargers in Nicaragua

[Richard A. Smith]

On 01/25/2010 04:31 PM, Daniel Drake wrote:
> Hi,
>
> What seems to be a lesser-common problem in the other deployments I
> have seen seems to be quite common here: chargers are breaking due to
> damage to the cable and the point where the cable enters the big green
> plug that goes into the power socket.
>
> Although these problems seem to be due to carelessness with the
> chargers, it would certainly help this deployment if the units were
> stronger. This is a significant problem here.
>
> A project partner here has been able to repair almost all of the
> broken units by reinforcing the cables and sometimes swapping out the
> components inside the charger unit itself. I'll send in more details
> once they arrive.

The abuse case is a trade off.  Without adding a lot of expense beefing 
up all the parts in the chain something has to fail its just a question 
of what.

In the XO we decided that we wanted the cable to fail rather than the 
laptop.  The mechanical coupling of the DC jack at the XO is stronger 
than the cable.  The plug is straight rather than right angle in hopes 
that it would separate from the jack in high stress events but if the 
force is perpendicular to the jack then its still going to bind.

Reinforcing the cable without careful analysis may cause failure at the 
XO rather than in the cable.

As new power adapters are much cheaper than new laptop motherboards they 
should probably take a closer look at how the cable is getting yanked 
and attack that problem rather than beefing up the cable.

-- 
Richard A. Smith  <richard at laptop.org>
One Laptop per Child