I have an old (but very useful) Linksys E4200v2 that has long suffered from the will-not-boot-while-warm problem that is mentioned here. This condition continues to grow worse with age, to the point that external fans no longer help. The device now has to be placed in a freezer for 5-10 minutes every time it needs to boot.
With the failure so easily reproducible, I decided to investigate and was hoping that a minor, replaceable component might be the cause. Using a can of freeze spray and working down to tiny drops on individual components, I have some pretty strong evidence that the Hynix TSOP flash is to blame.
That's all for now. Hope the information helps someone.