Help!! Started showing a shimmering picture (video included)

[JDB]

HELP! My MK1, HDG, non-TMSS, SCART connected Mega Drive has started showing a shimmery picture.

I'm using a 40"LCD (I know it's illegal - but my CRT is at my parent's) - The LCD picture isn't as good as a CRT anyway, but since 2 nights ago the picture has been shimmering like hell.. Almost like my eyes are spazzing out.

I've dont the basics, reconnected everything, tried to remove all sources of electronic noise (disconnect TV aerial e.t.c) and nothing helps.

Here's a video (although it's hard to make it out using my Macbook's shitty iSight camera)


pls halp

[ooXxXoo]

Do you have another Power supply that you can test the System with?...(preferably a Sega one)