My processor is of type AA.
I have my FP2 since February 2016. At first I had many random reboots. Mostly when the CPU was under heavy load (games, navigation,...). Using google maps navigation while driving was virtually impossible. The phone would always reboot sooner or later.
Over time it got better. I assume the software updates did the trick for me.
The biggest improvement came with
Fairphone OS version 1.10.1 - 19 December, 2016
- Fine-tuning of the voltage regulator settings for the LPDDR3 memory to ensure proper regulation in some units under certain conditions that could cause occasional crashes
I'm pretty sure my phone was affected by this issue.
My reboots always happened the same way: Freeze for a few seconds reboot.
Memory corruption leading to a freeze and a reset triggered by the processor's watchdog seems a realistic explanation for this behavior.
Now the random reboots are down to an acceptable level (about 1-2 times a week). And I can use heavy load applications like google maps navigation without reboots.