Arfa Daily wrote:

snip

JHC !!! Do you not understand the word "modern" ? Do you not understand the
phrase "... deals with monitors of all types on a daily basis" ? I repair
this stuff all day every day for a living. I have done for over 35 years. I
cannot remember the last time I saw a piece of kit of any description, which
employed a positive ground. My friend, who owns a computer repair shop, and
has done for many years, cannot remember the last time - if ever - that he
saw a monitor with an external power supply, that was not negative ground
with the connector sleeve as the negative connection.

With so much interconnectivity between household items now, there has had to
be a degree of standardisation on this issue, and it has evolved through a
general concensus amongst manufacturers, that negative ground will be the
convention.

snip

I have resisted commenting but can do no longer; I don't know about the U.K.,
but I frequently encounter negative center coaxial power equipment in my
work. These are not monitors, but a variety of consumer and industrial
portable devices. When the connector is not labeled and I don't have docs,
I will physically inspect the internal wiring or the pcb that hosts the power
connector and also do resistance measurements between ground planes and the
power connector contacts to determine ground. The assumption that ground
planes are negative is a given in most instances. As for the subjective
label "modern", that is a religious issue that shouldn't be a factor in
good electronics practice

Michael