Just reflowed a Samsung R70 board which wouldn't boot.
Stripped the board out. Shielded the surrounding stuff with ali foil. Started to heat it with a craft hot air gun (only 300w, bought to puff up ink according to my daughter). Couldn't get my digital temp probe to work above 150C (maybe bust) so I put a piece of solder on the chip where there was only solder resist. Heated it until the bit of solder melted and then for about 10 seconds more to make sure it had penetrated the chip's substrate. Allowed it to cool slowly by moving the gun away a bit at a time. Reassembled and now have a working laptop.
I did manage to drop the damn keyboard and broke the ESC key.
Now I need to make sure the Nvidia drivers underclock it so it doesn't get too hot.