The TU-10 contains an "Auto-Off" feature which shuts down the power automatically after it has not been used for 120 seconds. This feature can be useful to help preserve the battery's power. From the factory, the Auto-Off feature is set to "On."
Here's how to disable this feature.
1. Press and hold the up arrow button (^) on the back panel and then press the power button simultaneously on the top of the TU-10.
"P" flashes momentarily in the display. The Auto Off feature will now disabled until you turn off the power manually by pressing the power button.