[Galaxy Tab Q&A, Help & Troubleshooting] kangfu84:
Ok i've managed to simulate when the fault occurs. Its when i lock the Tab while another app is open.

Well, at least it happened everytime i locked the Tab when Logcat was open in the foreground.

Here is the log i got, ive only pasted from where i think it logged i pressed the power button:

12-21 02:47:55.213 E/WindowManager( 2498): Power key is pressed up mShouldTurnOffOnKeyUp:true

12-21 02:47:55.213 D/WindowManager( 2498): I'm tired mEndcallBehavior=0x2

12-21 02:47:55.213 E/WindowManager( 2498): pkgName:com.nolanlawson.logcat

12-21 02:47:55.213 E/WindowManager( 2498): className:com.nolanlawson.logcat.LogcatActivity

12-21 02:47:55.217 I/PowerManagerService( 2498): Ulight 3->0|0

12-21 02:47:55.217 I/PowerManagerService( 2498): Setting target 2: cur=41.0 target=0 delta=-2.7333333 nominalCurrentValue=41

12-21 02:47:55.217 I/PowerManagerService( 2498): Scheduling light animator!

12-21 02:47:55.217 D/KeyInputQueue( 2498): screenCaptureKeyFlag setting 0

12-21 02:47:55.443 I/PowerManagerService( 2498): Light Animator Finished curIntValue=0

12-21 02:47:55.443 I/power ( 2498): *** set_screen_state 0

12-21 02:47:55.443 D/PowerManagerService( 2498): enableLightSensor false

12-21 02:47:55.443 E/SensorManager( 2498): unregisterListener: com.android.server.PowerManagerService$12@48223588

12-21 02:47:55.443 W/SensorManager( 2498): Delay Candidate Listener 0 Sensor:4 delay:2147483647

12-21 02:47:55.443 W/SensorManager( 2498): Delay Candidate Listener 1 Sensor:4 delay:2147483647

12-21 02:47:55.443 I/Sensors ( 2498): sensors_data_delay handle=4 delay=2147483647 mMinDelay=60

12-21 02:47:55.443 D/Sensors ( 2498): sensors_control_activate active=00000012 sensor=00000010 new_sensors=2 changed=10

12-21 02:47:55.443 W/Sensors ( 2498): close Light sensor

12-21 02:47:55.443 I/Sensors ( 2498): set AK daemon delay=60 fd=66

12-21 02:47:55.451 W/PowerManagerService( 2498): CurLockF mPS:0 mUS=0

12-21 02:47:55.451 W/PowerManagerService( 2498): mPokeLocks.size=0:

12-21 02:47:55.451 D/PowerManagerService( 2498): sendNotificationLocked on=false

12-21 02:47:55.451 D/KeyguardViewMediator( 2498): onScreenTurnedOff(2)

12-21 02:47:55.451 D/KeyguardViewMediator( 2498): doKeyguard: IMSI=505023104565981

12-21 02:47:55.451 I/KeyguardUpdateMonitor( 2498): getSimState() : mSimState=READY

12-21 02:47:55.451 D/KeyguardViewMediator( 2498): doKeyguard: showing the lock screen

12-21 02:47:55.451 D/KeyguardViewMediator( 2498): showLocked

12-21 02:47:55.451 E/SensorManager( 2498): unregisterListener: android.view.WindowOrientationListener$SensorEventListenerImpl@482b3300

12-21 02:47:55.451 W/SensorManager( 2498): Delay Candidate Listener 0 Sensor:1 delay:2147483647

12-21 02:47:55.451 I/Sensors ( 2498): sensors_data_delay handle=1 delay=2147483647 mMinDelay=2147483647

12-21 02:47:55.451 D/Sensors ( 2498): sensors_control_activate active=00000002 sensor=00000002 new_sensors=0 changed=2

12-21 02:47:55.451 W/Sensors ( 2498): Accelerometer closed

12-21 02:47:55.451 W/Sensors ( 2498): Accelerometer go to SLEEP

12-21 02:47:55.451 D/KeyguardViewMediator( 2498): handleShow

12-21 02:47:55.455 E/RingtoneManager( 2498): getRingtone : file:///system/media/audio/ui/Lock.ogg, streamType : -1

12-21 02:47:55.455 V/MediaPlayer-JNI( 2498): native_setup

12-21 02:47:55.455 V/MediaPlayer( 2498): constructor

12-21 02:47:55.455 V/MediaPlayer( 2498): setListener

12-21 02:47:55.455 V/MediaPlayer-JNI( 2498): setDataSource: path /system/media/audio/ui/Lock.ogg

12-21 02:47:55.455 V/MediaPlayer( 2498): setDataSource(/system/media/audio/ui/Lock.ogg)

12-21 02:47:55.471 E/FastDormancy( 2573): [SCREEN_OFF] New FD Time: 5000

12-21 02:47:55.471 D/FastDormancy( 2573): [FD] INTENT ACTION android.intent.action.SCREEN_OFF

12-21 02:47:55.471 D/FastDormancy( 2573): [FD] mIsScreenOn: false

12-21 02:47:55.486 I/Ringtone( 2498): openMediaPlayer() mUri: file:///system/media/audio/ui/Lock.ogg

12-21 02:47:55.486 I/Ringtone( 2498): openMediaPlayer() isMidFile: false

12-21 02:47:55.486 V/MediaPlayer-JNI( 2498): setAudioStreamType: 2

12-21 02:47:55.486 V/MediaPlayer( 2498): MediaPlayer::setAudioStreamType

12-21 02:47:55.486 V/MediaPlayer( 2498): prepare

12-21 02:47:55.486 E/MediaPlayerService( 2401): Client::notify In

12-21 02:47:55.486 E/MediaPlayer( 2498): message received msg=1, ext1=0, ext2=0

12-21 02:47:55.486 V/MediaPlayer( 2498): prepared

12-21 02:47:55.486 V/MediaPlayer( 2498): signal application thread

12-21 02:47:55.486 E/MediaPlayer( 2498): callback application

12-21 02:47:55.486 E/MediaPlayer( 2498): back from callback

12-21 02:47:55.486 V/MediaPlayer( 2498): prepare complete - status=0

12-21 02:47:55.486 V/MediaPlayer-JNI( 2498): native_setup

12-21 02:47:55.486 V/MediaPlayer( 2498): constructor

12-21 02:47:55.486 V/MediaPlayer( 2498): setListener

Any ideas?