My monitor shows " Analog Power Saving Mode" on LG Monitor.

And goes off guickly.

I need somone's help to fix this problem

I need somone's help to fix this problem

There are two most likely possibilities. One is the monitor is defective and going into power save when it shouldn't. The other is it is not receiving a signal from the computer (problem with signal cable, computer's video adapter, etc.) and going into power save mode as it is designed to do. You can determine which it is by trying the monitor on another known good computer or another known good monitor on the same computer.