[SOLVED] Dell Latitude Laptop Motherboard Short Circuit

How to fix a death Dell Latitude laptop motherboard?


  


Ever plugged in a charger to find out that it's protection kicked in and there is no life inside the laptop?
We got this on a fairly regular basis and there is a nice way to fix it. It is not always easy but definitely worth while.
All you need is a determination to fix it and a little patience. 


Tools you need:

  • Multi-meter
  • Soldering iron (or hot air gun)
  • Spare motherboard 
  • Recommended is a microscope


Let's get started

The first thing we should do is unplug the screen because sometimes this is causing the issue.
Changes are small tho but we have to take out the motherboard anyway and it would be an easy one to locate. 

With the screen cable unplugged, try to put in the charger and see if the issue is resolved. 
If so, you have a faulty screen that needs to be replaced.

If not, let's move on and disassemble the entire laptop. We need to get the motherboard out of the laptop so we can repair it. 

When you are not sure how to take apart the laptop, just Google some video's from the model and disassemble, there are plenty.


The motherboard is out!

Get your multi-meter and put it on continuity mode. We are going to start probing the motherboard and locate the short.

 


Shorted areas

What we are looking for are most probably bad capacitors since Dell laptops have those very often.

When you look at your motherboard you see small capacitors in sectors. One or more of these sectors is shorted to ground. 
A capacitor must be grounded at 1 side and not at the other. So if you put your multi-meter at the ground you can start probing with the plus.
A good capacitor will only beep at 1 side. If the capacitor is beeping at 2 sides it means there is a short. 
Start probing some random capacitors and see if you can find the short. 

 


Capacitors near the CPU and GPU are always shorted.

To make sure that the CPU and GPU stay alive, the manufacturer of the motherboards keeps the capacitors near the cpu shorted.
Don't worry about those and keep moving on to capacitors not located near them. 



Found it!

After some probing around on the motherboard it beeped at some capacitors. This area is shorted to ground.

I started probing around in this area and found 2 more capacitors on the other side of the board which are also shorted.



Which one is it?

It's hard to tell when they are still attached to the motherboard. Start going with your instinct to remove them from the motherboard.
When they are detached it is possible to probe the capacitor itself to find out if it's the one that is causing the problem. 

My instincts were telling me it was 1 of these 2 or maybe both that are shorted so let's take them both out in 1 go.


Desolder the capacitor

I find the best way to desolder a capacitor is with a heat gun but it's also possible with a solder iron.
For more information on soldering, please check out remove bios chip with password.


Probing the capacitor.

Now that they are out we can find out if the capacitor itself is shorted, this is when it beeps from both sides.
You can simply check this with your multi-meter on continuity mode.



Found the bad capacitor, now replace it with a good one. 

You can either buy another capacitor or just take one from a spare motherboard if you have 1 laying around.
Just find one that is the same size as the faulty one and take it of the spare motherboard. 



Solder the spare on back on the place where you have desoldered the bad capacitor.



Now probe around and see if the short is gone. 


It is still shorted!

Don't worry, try the other capacitors that were shorted as well and remove those from the motherboard.
Replace them with spare ones. Keep doing this until the short is gone. 


Success!

It took some time but we have fixed the short! 

As you can see, the motherboard is booting and works like new. 


Congratulations !

There aren't many people on the planet that can fix a motherboard short circuit.
I am always amazed that a small thing can cause such a big problem but it's sure worth fixing it.
A motherboard replacement can cost you somewhere between a 100 and 300 bucks. 


Anyway, I hope you managed to fix your motherboard. Thanks for reading and hopefully see you soon.

Rob Michiels Posted by Rob Michiels