What motherboard has security tubes, air energy, set-top box motherboard, but I don't see a computer or TV.

The computer has a safety tube. The safety tube of the computer is in the iron box of the computer power supply, not on the computer motherboard, which is relatively weak.

LCD TV should have a power board, which should be found on it. In order to save materials, some power supplies are printed directly on the circuit board, and smaller printed wires are used instead of safety tubes. When the current is high, this printed line will burn out and play a protective role.