>I had a hunch that the problem was related to the thermal paste: When I disassembled it the first time, I had to scrape some thermal pads from under the Thunde

>I had a hunch that the problem was related to the thermal paste: When I disassembled it the first time, I had to scrape some thermal pads from under the Thunderbolt controller and the system hub. This left a large gap between the heat spreader and the chip. I’d tried to fill the gap with an extra big gob of thermal paste, but I suspected that the paste hadn’t gotten a good seal. Well yeah, that's a problem as thermal paste is only meant to fill in the microscopic irregularities of the contact surfaces and isn't some magical thermal bridge. Thermal paste has thermal properties on par with most condiments. Thermal pads are particularly bad. I would use a metal shim to bridge such a gap, not just more thermal paste.