PS2 doing a lot of noise and TV screen flickering after replacing cables

My PS2 Slim is doing a lot of noise (I don't know and I'm afraid of opening it to clean it and/or replace the thermal pads) and after changing the original composite cables for component ones the TV screen flickers (it goes back and returns to normal) for some seconds (it does this a lot of times). I no longer have the original composite cables.

Also, although minor problems, it not always reads a PS2 Memory Card (and I suppose a PS1 one) and a game disc (and I suppose a movie disc) but (I...

PS2 doing a lot of noise and TV screen flickering after replacing cables