Hello,
A scart to component cable will not improve picture quality significantly in comparison to a good quality RGB scart.
You could try a mains conditioner like aliEnRIK suggested and if you get one with multiple sockets then the peformance of your other components could also improve. You could also try a dedicated power cable - we have a lot of customers using our power cables on freeview and Sky boxes to great effect. From our product range I would recommend the Copper-line Alpha and we offer a 60 Day Money Back Guarantee so you can try without risk. Obviously there are lots of other power cables on the market from other manufacturers that you can choose from.
Hope this helps.
Kind regards,
Darren