I would like to write an activity that after clicking on a button turns off the screen and then turns it back on after 2 secs. I tried using the following code in order to power off the screen: WindowManager.LayoutParams lp = getWindow().getAttributes(); lp.screenBrightness = 0/(float)255; getWindow().setAttributes(lp); But it would only take effect when then onClick function returns. I tried running it into a handler but with no success. I need to find a way to force the setting to get applied before the function returns so that I can call the power on function 2 secs later on the same onClick call. I also found it very hard to wakeup the device afterwards. While this code works if I power off the screen using the physical button it doesn't seem to work when the phone is powered off using the technique described previously. PowerManager pm = (PowerManager)this.getSystemService(Context.POWER_SERVICE); PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.FULL_WAKE_LOCK|PowerManager.ACQUIRE_CAUSES_WAKEUP | PowerManager.ON_AFTER_RELEASE ,"Dev Tag"); try { wl.acquire(); wl.release(); } catch (Exception e) { Toast.makeText(this, e.getMessage(),20).show(); } Thanks you in advance for your help!