[Galaxy S 4 Q&A, Help & Troubleshooting] canaris1780:
Hi guys,

New owner of a S4 (GT-I9505 international) here with a problem. 2 days ago I noticed the screen wasn't rotating anymore. I used to rotate it portrait/landscape in applications like Camera or Internet (browser). The moment when it started to bother me was when looking at pictures with the phone in portrait and the image was landscape. Trying to rotate the phone didn't help. It was frozen. I called a buddy of mine who has some experience with Samsung devices and told me to verify the "Auto-Rotation" settings. It was all OK and enabled. Then he suggested turning the phone off and pulling out the battery and SIM card for 5 minutes and putting it all back. This didn't help either. Finally we got to the point where he told me to enter *#0*# in the Phone dialing application. As you might already know, this code gives you access to the "testing" hidden utility. There I tested all the options available. Everything was fine except for the Sensors and SensorHub Selftest.

In the Sensors section, all the tests failed, starting with the Accelerometer and ending with the Temperature. I uploaded screenshots taken during the tests. Please remember this started 2 days ago. Before this it was working perfectly. I don't recall making and major changes like updating any OS components or installing/running stress utilities related to sensors or device behavior. After doing some research online and reading about other people's similar problems I got to the point where I started to suspect a problem with the MCU (Micro Controller Unit). This component, according to Samsung, controls all the sensors and reads raw data from them without accessing the AP (Application Processor) this way extending the battery life. I believe the problem is here because it seems odd that none of the sensors are working all of a sudden. Can this component put the sensors into a sleep state and shut them down completely? Might this be the case here?

Below are the solutions I tried in order to revive the MCU and finally the sensors. I was all without success:

1) Turned off the phone and pulled the battery and SIM out. Put the back in after about 5 minutes. Result: sensors not working.

2) Reset to factory-settings from the settings option while the phone was in the working state (turned on). Result: sensors not working.

3) Rooted the phone, installed Clockwork Recovery, made a full system and applications backup and then installed custom ROM (two actually: PACMan, Google Play Edition (4.3)). I did this in order to exclude a problem related to drivers in the stock Samsung ROM, even if it was logical that Samsung being the owner and manufacturer of the device might have the "best" drivers and applications for inquiring the device components/sensors. I am aware this ended the warranty for me, but can I know it can easily be undone. Result: sensors not working.

4) Restored the original stock Samsung ROM. Result: sensors not working.

The utilities used for sensor testing were: Sensor Kinetics and Sensor Tester. Both can be found in the Play Store. On my wives phone, which is an old HTC Desire, both utilities picked up the available sensors and created graphs with the results. On my S4, I only got blank charts/graphics/results. In Sensor Kinetics for the Gyro for example, the message was "Waiting for the Gyroscope sensor...", just that, stuck.

If there are any other guys (or ladies!) out there who encountered this awful experience, please reach out and tell me if you found any practical solution, any other then just taking the device back to warranty. I'm open to any suggestions.

Best regards,

Andrei