[Samsung Galaxy S7 Edge Questions and Answers] madnav:
Hello Everyone,

I am posting this thread to explain a possible solution, after being unsuccessful with all of the other solutions found over xda; and hoping to be of help of others suffering the same issue.

Problem statement:

S7 Edge exhibits sleep of death (SOD) after being idle (possibly after entering deep sleep state). This is not a consistent behaviour for everyone though; for some it might enter SOD every time their phone is idle with screen off, and for some it might be as rare as once in a week.

Temporary Fix:

Force reboot with Power+Vol_down

Possible root causes and respective solution:

A. Corrupt files/partitions on storage (internal/external)

1. If using only internal storage, then backup data, and then format internal storage (Factory data reset or TWRP); end of process.

2. Else, if using internal + sdcard, then remove the sdcard and observe phone for persistence of this issue.

3. If issue persists then follow step 1, else format sdcard; end of process.

B. Inadequate CPU Voltage - Possibly using a custom ROM/Kernel that is discarding default voltage values/table

1. Install a custom kernel that allows voltage control

2. Install voltage control application (I prefer synapse)

3. Increment/decrement voltage value for lowest CPU frequencies of for both A72 and A53 core inorder to read Default value shown by Synapse (refer attached image)

4. Once you have observed the default voltage value, set it as the new voltage for that frequency and apply changes.

5. Repeat step 3 and 4 for rest of the CPU frequencies for maintaining stability.

Note: I had initially performed step 3 and 4 only for bottom 2 CPU frequencies; this initially reduced the occurrence frequency of SOD on my phone from 'once every hour' to once every full charge. This did not last long enough, and phone would again SOD frequently once battery dropped below 60%. For better stability, I have set voltage values to default for all frequencies.

6. (Optional Step) For all CPU frequencies that are lower than default_lowest_frequencies (A72: 728MHz, A53: 442MHz), set voltage same as default_lowest_frequencies. This is because some CPU's might not be stable below a certain_voltage, and it is always safe to assume that certain_voltage to be equal to voltage of default_lowest_frequencies.

7. Once completed, enable "Set on boot" in Synapse settings.

So far, I have tried multiple Kernels on multiple ROMs, and come to a conclusion that the issue for me was not related to any specific ROM, Kernel, or App.

I have made one more observation on this, that this SOD/Freeze does not occur while phone is charging/connected via USB.

Thus, I am suspecting following 2 possibilities as per my understanding:

1. Exynos SOC is indeed capable of running stable with lower voltages, but voltage/power regulation components are not capable of regulating voltages to defined levels without full charge.

2. Exynos SOC is not capable of running stable with lower voltages (18.75mV across all Frequencies in my case), this is the case for which Solution B applies.

I have not considered 'Weak Battery' as a possible cause, since the same should result in lower battery backup than SOD/Freeze; correct me if I am missing anything about this.

PS: I have tried capturing a logcat to determine the root cause; however, logs are not generated since it is a freeze caused by core hardware instability due to lack of power.