I'm having some problems tuning my bass with my amp - any tips?
Make sure to hit the MUTE button while tuning.
The Tuner is always running, but has limited display ability in its basic mode. Hitting the MUTE button will add another indication using the 'Bass tone control' as a tuner light-ring, which will most likely make it significantly more easy to tune your bass.
For more details, refer to this tuner walkthrough: