A Laptop Powering On But With No Backlight successfully Repaired
A university
student who needed this laptop urgently brought it to my shop for repair and
the main problem was no back light on the screen.
A very simple way
to identify a back light issue is to shine a light over the screen and you will
see what is being displayed.
I know the photo is
out of focus but if you look carefully into it you would see a dim logo of the
laptop being displayed.
There could be many
reasons for dim display; it could be a bad screen, bad back light board or
could be the screen socket on the board itself.
In my case was the
main screen connector on board because when I touched the screen flex cable a
brief flash of light appeared and then disappeared which could be a bad flex
cable or the socket itself.
When checked
through my microscope I found a lot of cold and bad soldering joints on that
socket and that require a micro soldering job. I got the flux tube out and with
a temperature of 400 and air flow of 60 set on my heat station I started gently
to heat up the connected after adding the flux on it. To make sure all the
soldering joints are connected firmly on board, I touched the socket pins with
my flat soldering tip after adding good amount of flux and when the job was
done, I let it cool down, clean it with IPA and assembled the screen and hoped
for the best.
The screen is alive
again but I could see another problem with it but all was well after clicking
the restart my PC option and it came on nice and neat.
The customer was
happy when I informed him of the repair and he rushed to pick it up because on
that laptop he had a lot of information that has to do with his graduation
thesis. I was glad I could help out in his matter and to that I could say... conclusion : if I were to found all the connection ok then I could trace the led driver output voltage and also the backlight condition .
