Hello all,

uniserver: Thanks for spotting that capacitor! It has now been replaced.

techknight: I didn't have any cans of compressed air so I gave the analog board a good scrub down with some rubbing alcohol and a toothbrush. I focused on the two components you mentioned.

I reassembled the the Macintosh and left it overnight. The next morning I switched it on and now it is not exhibiting any of the 'wobbly' raster behavior!

I'll do some more testing but I think that's the problem fixed!

Thanks for all the help