Other reports have surfaced of this problem, and it may also be causing the W510's left speaker to stop working in some cases. A similar problem appears to have surfaced in the T410. If I owned a new T410-series, T510-series, or W510-series laptop, I would turn it off while plugged into AC power, then vigilantly check for any heat buildup near the left speaker grille occuring within the first hour or two after shutdown. The problem seems to be worse if you close the lid of the laptop, since that traps the heat. If you feel any heat buildup, I would unplug the machine from AC power and call Lenovo tech support. If you continue to feel heat buildup even after unplugging AC power, then I would also remove the battery from the laptop.
Apparently, at least some part of the laptop remains turned on even after you've shut it down. The reason the laptop's base gets hot in that area, is likely because that's where the heatsinks for the chipset enter the fan. The heatsinks have a series of fins on them inside the fan assembly to radiate heat into the fan's airstream. If the fan isn't turned on, or isn't running fast enough, you'll instead experience a build-up of heat in that area. In any case, none of this should be happening in a laptop that has been turned off.
One other user who had this problem had shut down his W510 and closed the lid. He reported that the plastic had then buckled in the same area that you describe as being hot. He also found condensation on the screen just above the buckled area. His left speaker also stopped functioning. It turns out that the wires feeding the left speaker are taped onto the top of that same area of the heatsink. So their insulation probably melted as a result of the heat, and the vapor from that may have caused the condensation on his screen. He also began having memory errors, which are probably linked to the overheating.
He thought his left speaker may have shorted out, causing the problem, but that's unlikely. I have several degrees in electrical engineering, and I don't see how a small malfunctioning speaker, that was playing no sound, while the laptop was supposedly turned off, could generate that kind of heat. Also, it's just too much of a coincidence that the heatsinks enter the fan in the same place as where the overheating occurred. So I think the heat is coming from the heatsinks. Anyway, here's his report: |