The Samsung Galaxy S4 has been around for quite some time. Nonetheless, it has been in line for several updates and tweaks that some users have started experiencing problems. Device problems are only natural but it pays for users to understand why they experience such problems and how to fix it. Some of the provided fixes include those specific to particular OS updates.
Home Button Problem
According to a user from The Droid Guy, following update of Android 4.4.2, the home button fails to direct the user to the home screen. Given the home button directs the user to the apps opened recently instead of the home screen, it may be ideal for users to press the home button quickly than prolonged. Pressing on the home button longer brings the user elsewhere than the home screen.
If the Home button fails to respond then the S Voice's "Open via home key" option should be disabled. If the device does not respond at all then it is best for users to take it to the technician. A factory reset may also be in order.
OTA for Unrooted Phone
If users root their devices but the phone did not install the Custom ROM then they can still receive OTA updates. Unrooting a device or not will not be a problem. Likewise, for users that rooted their phones and installed the custom ROM, they have to return the stock firmware. If not, OTA updates will not be possible. Rooting does not stop the updates since it only opens the device to other update opportunities.
Some users also expressed having problems after locking their phones. The device will turn back on then goes black after a few minutes. Often, the problem lies with a third party application running the device all of a sudden.
Boot the Samsung Galaxy S4 to Safe Mode to check the problem. This should disable all third party programs. If the problem does not exist anymore then it is a third party problem. Nonetheless, if not, then a pre-installed app may cause the problem. A Wakelock Detector is a good program to install to check which programs are waking the device up. If this does not work then do a factory reset.