Apple ][+ too. In addition those 72x chips would fail with time. We figured out that a can of compressed air was handy. Power on. Wait for machine to freeze. S

Apple ][+ too. In addition those 72x chips would fail with time. We figured out that a can of compressed air was handy. Power on. Wait for machine to freeze. Spray a chip with compressed air to cool it. Try again. If it stayed working it was probably that chip. Thank goodness they were socketed.