Instructions
Clean the disc. If it is only one disc that cannot be read, the disc is either scratched or dirty. Clean the disc using a small amount of rubbing alcohol, a lint-free cloth or cleaning fluid that can be purchased from video game and toy retailers.
Clean the console. Dust and hair can accumulate in the PS2 disc tray if it is left open. Use a can of compressed air to blow away anything that might be trapped inside.
Use a laser lens cleaner. This also helps to clean any grime that may have accumulated in the console.