Lenovo's motherboard, where is the power pin inserted?

Generally, the jumper pin printed with PW is next to the motherboard, or see the motherboard manual.

if there is no

Just try the function jumper areas one by one.

Of course, you also need to know the jumpers such as USB2.0 and front stereo, except for these jumpers.

Power switch jumper does not distinguish between positive and negative directions.