(UK) Snes video problem, vertical line glitches

I bought this SNES a while back I think last year possibly earlier, for £30 with a power adapter and controller and RF cable, i have been meaning to upgrade to s-video. Anyway after using it for a while i noticed these lines that appear on background/text items in any game I put in there. The problem, isn't very bad as you will see from the pictures but it is rather irritating while playing. I tried all the basic troubleshoots, cleaning contacts on the SNES, cleaning cart contacts, using a different psu, using the multi-out rather than RF, different T.V and yeah no luck. at least I cleaned the system and carts though . While taking a look at theSNESit looked like someone else has worked on the system in the past. here are the pictures: http://imgur.com/a/4osYA Also I PM'd Retro Junkie and he said it is probably either the RAM or PPU chips, if it is then what chip is it most likely going to be.