Here are some examples of backlight failure:
(Some systems will display no image when the backlight is faulty)
Very faint Acer logo
(white spot is camera flash)
Pink flickering backlight
(normally the Vaio logo is white)
Backlight current leakage
can
interfere with video signals
Our engineers repair backlights on Sony, Acer, Compaq and HP laptops
Above Acer 1710 fixed
We repaired the inverter
Above Sony Vaio fixed
Colours are perfect. No flicker.
This inverter was repaired by
replacing a transistor
Another PERFECT Repair
37603
LCD
BACKLIGHT REPAIR FAQ:
Q. Do I need to replace the whole screen?
A. No - it's far cheaper to repair
the faulty parts. Manufacturers like to think of the display screen as one
spare part unit. This makes it easy for their field service engineers to exchange displays rather than diagnose
the real fault and repair it - can save hours of engineer time. This is fine
for corporate customers with vast laptop maintenance budgets, but most
home and small/medium business users can't afford to pay £400-£700 for a
display screen. We actually repair the fault within the display. Most
repairs cost less than 50% of what the manufacturers charge.
Q. What causes the backlight to fail?
A. A backlight fault can occur if the laptop is dropped or if a lot of
pressure is applied to the base of the LCD panel. Electronic or cable
failure can sometimes result in a faulty light. The motherboard controls
the backlight brightness and a failure there will also lead to a dark
screen. The backlight uses very high voltages to power the fluorescent
light (CCFL). The circuits can fail due to overheating, arcing or current
leakage.
Q. What causes the CCFL to fail?
A. The CCFL is a small scale fluorescent tube, similar to office lighting
tubes. The LCD CCFLs are 1.5-3mm in diameter and 30-400mm in length. They
can easily break if the laptop is dropped. They also wear out and can
start flickering or change colour to a dim red/pink. Working tubes should
emit a bright white light.
Q. Why is the image on my external screen perfect?
A. A lot of customers wonder why the image is perfect on an external screen
if the laptop is faulty. The reason is quite simple, the backlight only
effects what you see on the laptop. Your external screen has it own
working backlight or it may be a CRT screen which does not need
backlighting.
Q. Can
I buy a backlight to fix the dark screen?
A. No - the dark screen problem can be caused by the CCFL, inverter, cables
or the motherboard. We used to sell backlight parts, but most were
returned as the customers had failed to diagnose the problem correctly and
ordered the wrong parts. Some customers tried to change the CCFLs and
ruined very expensive LCD panels. Installing a CCFL is a difficult task
even for an expert. Most first timer attempts to change the CCFL will end
with a dead screen - that is why our engineers are trained on broken
panels. They remove and correctly reinstall at least ten CCFLs before
working on a customer laptop. This job is best left to trained engineers.
Q. What is the inverter?
A. The inverter is a small circuit found under or behind the LCD panel. It
converts low voltages to the higher voltages required to power the
fluorescent tube. It also controls the brightness of the screen. A faulty
inverter can cause the screen to flicker or go dark. Care must be taken
when installing an inverter as a short circuit can kill your motherboard.
Also, yanking the cables can cause damage to the LCD. Damaged cables are
very difficult to repair or replace - great care is necessary.
Q. I get a blank white screen. Is it the backlight?
A. This is not a backlight fault. Please don't try to buy inverters and CCFLs
to rectify this fault - your backlight is fine, hence the white light.
This problem may be related to the video chip, cables, LCD or motherboard
failure.
Laptop Faults:
UK REPAIRS INFO
Marlborough House
We ONLY
service laptops for
UK customers.
We ONLY
service laptops for
UK customers.
Business
Hours
Mon-Fri 9.00am-5.00pm
Saturday 10.00am-2.00pm
Visitors welcome
Customers are always
welcome to visit us and discuss their laptop repairs with our engineers.
Parking
Info
You can park in the
residents bays on Bruce Road at all times EXCEPT: Mon-Fri 10-11am
& 2-3pm
(PLEASE AVOID THESE TIMES)
Tube/Rail
Harrow & Wealdstone Station is served by National Rail and London
Underground Bakerloo
Line services.
We are a walking distance away and on the same High Street.
Mailing
Info
Most customers send us their laptops by
mail. The average cost of sending a laptop to us using the post is £18
for next day delivery with insurance.
