Fixing a 6 switch Atari in the UK - dodgy power socket?

[Spector]

I got a modded NTSC Atari 6 switcher, and it's in decent nick and the mod isn't too bad. However, I then noticed the picture flickering, then the colours started wobbbling ie ms pacman went from blue to black to green backgrounds, then I noticed the odd glitch in the graphics, then the picture went out completely. It's almost like the power socket is dodgy and it's affecting the picture. Is there anyone in the UK capable of fixing my good ol' 6 switch Atari??