Tag Archives: laptop

Laptop has no video

Published by:

Hello again,

Recently I had a service call about a laptop that had no video at all.

The obvious reason and most common one is the inverter board (backlight can be a culprit too). If that goes bad, then the laptop screen will appear black. Another possible reason is the video cable; it can get damaged or become unplugged. The worst one is when the video card goes bad.

So in order to determine which of these is the culprit, you can do several things:

  • make sure the laptop receives power. When plugged in, look for the LED lights indicating the power on the laptop, is these are on, then your laptop receives power.
  • next, shine a flashlight on the laptop screen; if you can see a faint image on the screen, then it is the backlight or the inverter board. They can be tested with a tester to determine which is the bad one.
  • if there is no image on the screen when using the flashlight, the try to plug in an external monitor, to see if you can get video; if no video on the external monitor, then the problem is with the video card;
  • the way to determine if the problem lies with the video cable, is to open the laptop case and take off the screen, and manually check if the video cable is damaged or unplugged.

The good news is that all of these issues can be fixed with a part replacement.

First things first: have an antistatic wrist strap, every time you work inside a computer case.

Step by step instructions:

  1. Check your laptop specs to see if you have an integrated video card or a discrete one; if you have an integrated card, then the whole motherboard will have to be replaced, otherwise, only the video card needs replacing.
  2. We determined that the video card is bad and it is integrated on the motherboard; we need to find the correct part and purchase it.
  3. with the new motherboard at your side, start opening the laptop case;
  4. unplug the laptop ac adapter and take out the battery; set them aside
  5. take out the HDD, DVD/CD  units by flipping the laptop upside down, and removing the screws from the bottom of the laptop.
  6. once these are out, start removing all the screws from the bottom of the case. Keep them in a safe spot, and preferably separate from the rest of the screws coming out later;
  7. flip the case again, and remove the top plate holding the power button;
  8. remove the screws holding the screen hinges, and set the screen to the side, watch out for wires and cables; If the problem is the inverter board or backlight:
  1. remove the screws holding the cover on the screen, and take the monitor from it’s case, be aware of the cables and wires.
  2. Replace the backlight or inverter board, plug the cables back in;
  3. put the monitor back together and connected it to the main part of the laptop;
  4. after all screws are back in and everything is connected properly, check to see if the screen will light up. That is it for the inverter board replacement.
  • take out the keyboard, being careful not to damage the connector for the keyboard; there are two tabs on the sides, that need to be pulled up, the connector will slide out then easily.
  • remove the top part of the case;
  • unscrew the motherboard from the bottom case, if necessary, remove the screws holding the serial and parallel ports (depends on your model), for easy motherboard access.
  • remove the motherboard and set it down preferably on an anti static mat;
  • start porting the memory, wireless, fan, cpu, etc  to the new motherboard.
  • once everything is on the new motherboard, replace it back in the bottom part of the case and screw it down if necessary.
  • replace the top part of the case, and put the keyboard back in ( don’t forget all the wires and cables that need to be plugged in the motherboard);
  • attach the screen back on, and start replacing all the screws in the case
  • replace the HDD, CD/DVD, etc, back in the case;
  • at this point, you can plug the laptop ac adapter and turn it on to see if you get video.

If all the screws are back in and all the wires attached, then the laptop should power on, and video should be working just fine.

That’s it, hopefully you didn’t go crazy working with all the tiny screws and pieces.

My advice, if the cost difference between replacing the part or getting a new/used laptop is not too great,  don’t even bother,  just get a new one.

Good luck and ask your questions; I’ll do my best to answer.