Oh I go through all the process "figure out WHAT is not working, then figure out WHY" every time like for example; No power, ok may not be pluged in (dah), power cord could be broken inside, maybe a blown fuse inside and beyond the fuse is where I stop because I don't know what to do next. Yes I will look if there's any visual problems like burnt components, odd smell, deformed plastic, broken traces, cold solder joints etc... Beyond the fuse I have no idea on how to find shorts or to do trouble shooting. That is why I started to watch for some troubleshooting vids on youtube but mostly it's all hindu or too advance for me. I'd like to see a video that shows me step by step AFTER the fuse.
My monitor I know that the LED in front doesn't light up BUT the fuse isn't broken so I know power supply IS working, there isn't any video on the front screen and at the neck of the tube there isn't any light in it. So there's power going in through the power supply and then I don't know what to do next. There is a very faint wining sound coming out of the speaker and even if the speakers aren't plugged in I hear that faint wining sound. Here's the sound file that I have recorded and been amplified to have a better sound.
No, you don't know the power supply is working, only that power
might be going into it. Have you measured the AC line going into the actual power supply? What are the output voltages? What is the ripple on the output rails? If you can answer those questions, only then can you say the power supply is working, then you can start looking at the next piece of the puzzle.
If you see a problem there, what type of power supply is it? Linear or switching? That makes a big difference in how you troubleshoot.
You're assuming the power supply is working without verifying that, which is a mistake. The LED not lighting up is a clue that the power supply may have a fault (it might also be a shorted cap on the power rails somewhere) but you won't know unless you actually measure it.
A shorted cap somewhere may pull the power supply voltage down enough so some of the circuitry doesn't work, but not draw enough current to blow the fuse.
If you don't have a schematic, it gets tougher. Look for fixed output regulator chips which will tell you what the voltage should be. The filter cap voltage rating will give you a clue as well. Look for parts which get very hot which may indicate a short. Linear regulators may run hot, so you need to have an idea about what's going on.