Not a lot to go on here, Prabhdeep
Need the full model information
Acer Aspire 5535-5050
Post back in a Comment, or Reply; at end of this solution
An LCD screen does not produce light,http://solutions.3m.com/wps/portal/3M/en_US/NA_Optical/Systems/BehindTheScenes/Optics101/
Click on the monitor icon
Because of this the LCD screen needs an additional light source.
A Backlight is the additional light source.
A Backlight can be a CCFL, (Or more than one), or a series of LED's.
(Light Emitting Diode)
CCFL = Cold Cathode Fluorescent Lamp (Bulb)
Similar to Fluorescent lighting used in homes, and businesses; but on a MUCH smaller scale.
Average thickness is 2mm, or a little more than 1/16th of an Inch.
Or about the width of this capital letter -> O <-
Average length is almost as long, as the LCD screen is in height.http://www.laptoprepair101.com/laptop/2007/12/09/replace-laptop-backlight-ccfl-lamp/
View the last 8 photos
(Do they break easily when trying to remove, and replace?
A screen Inverter is used to convert the power from the laptop, for the LCD screen, and Backlight.
If the laptop uses LED backlighting, it MAY or MAY NOT use a screen Inverter.
Generalized thinking (Can also be stated as 'Rule of Thumb'), is that if the laptop uses LED backlighting, it does NOT use a screen Inverter.
I also feel into this line of thinking, since none of the LED back-lit laptops seemed to use a screen Inverter; that came to the shop.
I have found this to be a fallacy from on here,......FixYa.....
I have looked up two laptops using LED backlighting, and discovered they also used a screen Inverter.
Now I post LED backlighting may, or may not use a screen Inverter.
Seems when LED backlighting first came out, a screen Inverter was used on some models.
Also seems as the LED backlighting technology progressed, no screen Inverter is used.
90 PERCENT of the time, the fault for bad Backlighting can be attributed to a bad screen Inverter.
Of course, this IS IF the laptop uses a screen Inverter.
For a laptop with LED backlighting that does not use a screen Inverter, and backlighting is bad (Dim, or non-existant), the next hardware part in the diagnoses to replace, is the LCD screen.
I now await the information I asked for above.
Then we can diagnose together.