Numerous Galaxy S6 and S6 Edge users have reportedly been affected by the Deep Sleep issue, wherein the device fails to enter deep sleep mode when its display is turned off and consequently it leads to severe battery drain with increased processor usage at all times.
Quite fortunately, the folks at Droid Views have uncovered a couple of easy ways to overcome this issue: re-flash the original Galaxy S6 stock firmware or force your S6 to enter Deep Sleep mode via terminal commands.
1) Re-Flashing stock recovery or official firmware
Re-flashing the stock recovery file for your device model and firmware build is the easiest method to restore your Galaxy S6 to factory settings, which allows you to remove all unwanted apps and custom settings that could be causing your device not to enter into Deep Sleep mode.
Alternatively, flash the stock recovery file meant for your device model and firmware build in order to fix the deep sleep issue.
2) Force Deep Sleep manually
In case you failed to back up your data and hate losing the same with stock firmware flashing method, then your best bet would be to force your Galaxy S6 into Deep Sleep by applying a few terminal commands. Note: Some of these steps will require your devise to be rooted. Check out our simple guide to root Galaxy S6: Root Galaxy S6 and S6 Edge without tripping KNOX via PingPongRoot.
Steps to fix Deep Sleep issue on Galaxy S6 and S6 Edge
Step 1: Download and install Terminal Emulator app on your Galaxy S6 via Google Play Store.
Step 2: Launch Terminal Emulator app from the app drawer.
Step 3: nable root access on your Galaxy S6 by typing the following command and then confirm the action by choosing 'Yes': su
Step 4: Now enter the following commands in succession:
This is the simplest way to fix deep sleep issue on your Galaxy S6, when nothing else works.
[Source: Droid Views]