akirasukura,
In most cases, the player can get warm, even if it's not in an enclosed armoire or system rack. This is considered normal.
If you think it's excessively hot to the point where it will damage something (warp wood, etc), then that kind of heat is not considered normal and I might consider contacting service.
Let me know if I can help further.
--HDTech
Is it normal for the bottom of the player to be excessively hot after playing through a whole movie? It was surprisingly hot on the bottom of the player and is worrying me. Anyone else notice this?

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