Clean your thermal module surface as it must have deposited dust on the cpu and gpu section of this module that has contact with the cpu and gpu. Take this module out and clean it with alcohol and repaste the cpu/gpu and clean the fans. As the thermal module gets affected first, also check the motherboard circuitries around the DC port and connecting plug that connects to the power stage of the mobo for any signs of any overheating or discoloured chips that may still be working but they emit this smell, like capacitors, mosats, as that could also be a cause of this smell.