When it is turned on, the tuner will play a scale to let you know it’s on.
If the tuner is set to semitone tuning mode it will play 4 low-frequency flat tones.
When a guitar string is sounded, the tuner will play the note it believes the string is playing before either playing three sharp or three flat tones, depending on whether the string is sharp or flat.
The duration of these three tones will depend on how sharp or flat the string is (long tones if the sounded string is very out of tune, short tones if it is nearly correct).If the string is in tune, the tone associated with the string will be repeated.
To dismantle the guitar tuner remove the battery and battery holder.
Undo the two screws on the back of the tuner and gently prise the two halves of the case apart (I used my fingernails).