On 24/07/14 19:35, Baron wrote:
aeio prodded the keyboard

I noticed a tingling from contact with a USB lead of an external
Hard Drive.

Investigating this led to the PSU, the plug of which has a high
voltage on the outer connector compared with house earth. It was
varying between 70 and 110V.

(I did not check the voltage of the output which I have no reason to
doubt was correct - 12V I think it should be)

The PSU is a three pin plug. Presumably the earth connection is not
being used.

Is the PSU faulty?

Check the outer shell to earth pin with an ohmeter.


I had it packed to return actually - but have opened it up again - and
see the earth pin is non conductive.