My Dell latitude e5440 laptop not turning on

@asif17812 start with the basics. Disconnect the power from the computer by unplugging the power cord from your computer. Disconnect all external devices from the computer. Remove the battery 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.

First you want to check your power supply. Make sure it has the proper voltages. Check to make sure connectors are not bend etc. After that, check the charging port. Clean it of any debris etc, use a few puffs of air to clean it out. Check the DC-in jack of your laptop. Make sure there is no corrosion, debris etc. that prevents it from working. 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 Adding images to an existing question.

Of course, you may also have to consider replacing the battery. A depleted battery can no longer be charged. However, it should not prevent your computer from coming on, if it is connected to the AC adapter.

Of course, it is also possible 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.

For any further troubleshooting and to work on your computer,. Download the manual from here Luckily Dell places all of the repair information into the owner's manual.

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

While you work on your computer, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has the same problem as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.