problems with older mvs carts!!!!

hi , this is my first posting here and i hope someone can help me. i have a 4-slot mvs and i have problems when i play the old carts that i have: baseball stars,ninja combat and top players golf. when one or some are used in my mvs i get sound glitches for example like in the neo-geo statup screen and when i am playing game. also graphics glitches for example lines through characters.i dont seem to have any problems with newer carts except sometimes some games arent recognized until the second cycle of game selection and then they work fine. is there something possibly different with the old ones? is it my machine? I have tried cleaning them and changing order of which slot they are in. These carts are from different people not the same source and i have checked and they are not boots. whats going on? help me!!!!

Hi phoenixforever, welcome to the forum.

Cart and socket connections have to be squeaky clean, try cleaning again.

http://www.hardmvs.com/html/cleaning.htm
http://www.hardmvs.com/html/slotCleaning.htm

thanks for reply, i have already cleaned the carts really well and the slots too. could there be anything else? why just the older ones?also does having one glitchy cart effect play on another cart in a different slot?