Saturn SCART Isuues

Have just bought a SCART lead for my Saturn, but am having some
difficulties. When i plug the Saturn into the TV in the spare room, it
plays fine through a SCART cable into the TV. Nothing else is plugged
into the TV, except an aerial for terrestrial TV.

However, when i plug it into the TV in my room, the screen just turns
black and there is no audio. Ive tried switching to all AV modes before
and after i switch the console on, unplugging everything expcept the
SCART, and using a different mains plug, but its just a bare black
screen everytime. My SCART sockets definetly works on both TVs, niether
of which have ever had any trouble before, so both TV's work, as does
the Saturn and the SCART cable. The power cables i have used too both
work ion the spare room, but not in mine. The setuo also works in the
kitchen too. There are no loose connections or broken components i am
99% certain.

Does anyone have any ideas at to what the problem could be please?

Thanks in advance.

EDIT - I seem to be gewtting somewhere wth the first problem-when i
turn the Saturn off, as the button is pressed, i get a glimpse of the
screen for about a tenth of a second. Maybe a power issue? But both
TV's tested are using mains multiplug adapter things?