My Canon MP237 shows error 1200 even when there's no paper jam. What else could be wrong?

If your Canon MP237 shows error 1200 without a visible jam, the issue might be with the paper feed rollers being dirty or worn. You can try cleaning the rollers gently with a lint-free cloth slightly dampened with water. Also, ensure the paper loaded is not too thick, too thin, or creased, and that it's properly aligned in the input tray.