Here is a simple trick.Take a A4 size paper and draw six strings and 12 frets ( a neck diagram).On the side write a set of chords say Amajor/C#min/D major/ D minor.Now for each of these chords write down the chord tones namely ( A,C#,E),(C#,E,Ab),(D,F#,A),(D,F,A). Now for each of these triads for the chords above plot all the notes with different color dots all over the neck.You will get 7 A's,6 C#'s,8 E's,6 Ab's,6 F's,7 D's.Counting as firmly as you can slowly play through each set of triads as the corresponding chords move.Mix the octaves and strings as you get comfortable.Do not play quickly, and you will soon be feeling every change that occurs.Please try this with every chord progression you hear or see.You will be able to outline the chords with simple fragments before you start with scales,arpeggios and other devices.As you quietly do this, I will gradually give you more devices per chord never forgetting the fact that you KNOW the chord tones.Hope you enjoy this its a primary and imperative exercise to align your ears with chord changes.Paste the paper on the wall or on a music stand and religiously make simple tunes based on the 3 notes per chord principle.You will soon be able to locate a note on any string improving fretboard recognition.