Abnormally high number of laptop chargers failing.
We have a spate recently of Dell laptop chargers failing. We expect them every so often, but I've just removed 7 faulty ones from one cabinet which is a very large number.
The thing we've noticed about the failed ones is they are all the same design - Dell have 2 or 3 different power supplies - they all output the same, but they have different AC leads. The one's that have failed all have the 2 pin AC inlet with no earth connection which I think is significant. There were 3 pin power supplies in the same cabinet, and none of these have failed at all.
Has anyone else had a large number of these fail, or any suggestions as to why these particular chargers are failing more than the rest?