Low Power Mode belongs to sleep
Amazon says supported Fire TV devices automatically enter Low Power Mode when they sleep, and Select wakes them. It is an idle power feature, not an alternate streaming-quality mode. Amazon also says it cannot be disabled on devices that include it.
If the screen goes dark, note whether the device was idle, whether sound continues and whether Select restores the interface. Those observations help distinguish sleep from a persistent display or app failure.
Check the selected idle behavior
Amazon lists settings that affect the efficiency achieved in the idle state. Its documentation also distinguishes a black-screen sleep choice from turning HDMI off. A dark panel does not necessarily reveal exactly which device state is active.
Review the actual model’s settings instead of applying a promised universal switch. Keep a note of any wake-related or always-listening features that are enabled so later comparisons concern the same arrangement.
Test a normal return to viewing
Wake the device with the documented control and verify that the Home Screen and intended app respond. If the app alone fails after wake, report that narrower behavior separately from the power feature.
This page does not claim measured standby consumption or savings. It explains the automatic state Amazon documents and the observations needed to describe a real wake problem.
Questions answered
Can I switch off Low Power Mode on a device that includes it?
Amazon says the feature activates automatically in sleep and cannot be deactivated.
Does a black screen always mean HDMI is off?
No. Amazon distinguishes black-screen behavior from HDMI-off behavior in its idle-state guidance.
Sources & further reading
Official references for the subjects discussed. Service terms and device software can change.