According to the Jensen manual for their 12V televisons they do not have an alarm function. The only auto-on feature I saw was if you have an HDMI CEC device attached the TV will automatically turn on when the device is activated. You can turn off that feature by going to the televisions "Picture" menu and scrolling down to the HDMI CEC option and turning off the "TV Auto Power" selection. If you have a device attached via an HDMI port (such as a DVD or stereo) make sure it does not have an alarm function and if it does make sure it's turned off.