[hedora]

All of those things are protected. If the firmware melts the board, the CPU overheats, or the replacement part shorts something out then the warranty is void. However, if the failures are unrelated, then it's fine.

I once caught a motherboard on fire, then found some unrelated mechanical issues with it. (It still worked, except for the bad connector.)

The burn marks were cosmetic, and the shop sent me a DOA replacement. (That's more a story about the shop being awesome, but they were technically legally obligated to honor the warranty.)