There is a monitor power supply behind the computer power supply, which outputs 220V V. Can I not plug it in? And directly use the power grid 220V instead of the display point source?

There is no need to plug it in, and if there are enough slots in the wiring board, it is recommended to connect it directly to the wiring board and plug it into the host power supply, which will bring power pressure to the power supply.

For example, the computer power supply is rated, generally 220W~300W or even higher. Generally speaking, the higher the wattage, the more expensive the power supply, and the demand for the host is generally less than 200W ~300W or even higher (the higher the configuration, the higher the wattage). When installing, generally choose a power supply with a slightly higher wattage than the main engine. If you add a monitor now, the wattage of the power supply will increase. You need to use a more powerful power supply. If the power supply remains the same, it will be a 220W, and the total power of the mainframe will be 200W W. Now, if you connect a 40W LCD monitor, the mainframe and the monitor will need a 240W computer. This 220W power supply is overloaded, and problems will occur after a long time.

PS: The main power supply with monitor power supply is usually an old computer. In the past, the power supply was much more powerful than the main engine, so this socket will be available. If the host configuration has not changed, you can connect to the host power supply, but it is recommended to connect directly to the terminal board.