The tempo does not change when I operate the tempo slider on the master deck.

To prevent sudden changes in the tempo, if the tempo (BPM) being played on the master deck does not match the tempo corresponding to the position of the tempo slider, the unit is designed so that the tempo does not change until the tempo slider is set to the position corresponding to the currently playing tempo.

The BPM value corresponding to the tempo slider's position is displayed on the LCD's playing speed display. Operate the tempo slider to match this with the value displayed in the square frame directly below this. After this is done, the tempo slider can once again be operated.