Asus vivobook X505B

have you cleaned it recently if not that is probably the best thing to do this will also give you the opportunity to check that everything is plugged in and other basic things

@evelynkhombane let us know how you know that your laptop turns on since northing seems to be working. I assume you just have your power LED on. Let us know exactly what it is that you see that makes you say your laptop is on. Also let us know if anything happened to your laptop prior to this. If absolutely nothing happened to it, it sounds like a BIOS or motherboard issue.

Start off with the easy things. Disconnect the power from the computer by unplugging the power cord from your computer. Disconnect all external devices from the computer. Now hold the power button depressed for about 30sec-1min. Reapply the AC power adapter and see if your computer does show any sign of life.

Next you want to check your power supply. Make sure it has the proper voltages. Check to make sure that the connectors are not bend etc. Check the DC-in jack of your laptop. Make sure there is no corrosion, debris etc. that prevents it from working. Clean it of any debris etc, use a few puffs of air to clean it out. If none of this works, get a ammeter and see if your laptop draws any amperage from the charger. After that, you need to check and see if your motherboard even gets power. For that of course, you need to open it up. Post Some good pictures of what you see. That way we can see what you see.

There is also the possibility that this is a bad RAM module or a bad LCD. So remove the RAM, clean the contacts with a pencil eraser. Do it gentle so as to not destroy the module. Replace it and restart. If you have more than one module, remove it and just leave one connected.

Connect and external monitor and see if that shows anything different when your laptop starts up.

Let us know how things are working out with each check/test.

iFixitでの質問に画像を追加する方法