It’s ugly but useful. For $9.99–$14.99 (typical price), this PDF is a cheap insurance policy against a costly service call. Buy it if your KU-400 is acting up; skip it if the unit is running perfectly. Would you recommend this to a friend? Yes – but only if they own a KU-400 and know which end of a screwdriver to hold.

Overall Rating: ★★★★☆ (4.2/5)