Acer laptop no backlight on screen

contact acer service center

it might be the backlight module.

or a loose connection from the mainboard to the backlight module.

you have to open the laptop and the screen cover to see the problem.


goodluck

Since you have video with an external monitor your lcd panel is going out.This is not hard to repair only costlyhttp://www.insidemylaptop.com/remove-lcd-screen-replace-inverter-board-acer-aspire-5100-laptop/

1.The Function key (Fn), and the F6 key are pressed to turn the Backlight off to conserve power.

2.The Fn key and the right side arrow key, are pressed to increase Brightness.

You have a TFT LCD monitor screen. (Thin Film Transistor)
The LCD screen cannot be seen clearly without a Backlight.

The Backlight is a CCFL. Cold Cathode Fluorescent
tube. Resembles a small fluorescent tube used in residential, and commercial lighting.

The Backlight can go bad after time, and weaken.
If so, it will have to be replaced.

Sounds easy, it isn't.

The TFT LCD monitor screen is made up of layers. It's enclosed in a thin metal frame. Resembles a picture frame.

The frame is removed, after removing the LCD screen from the laptop's top cover.

The LCD screen transparent outside layers, are separated partially from the rest of the LCD screen.
The Backlight is removed out of the side.

This gives you an example of removing, and replacing an average Backlight,

http://www.laptoprepair101.com/laptop/2007/12/09/replace-laptop-backlight-ccfl-lamp/

Recommended job for a pro.

You need to fix the boot manager problem first by connecting an external monitor to the laptop so you can see and do a system repair.

As for the backlight problem :-
You could have a faulty CCFL lamp or inverter, To determine if you have a LCD screen, inverter or video card problem, read this and follow these instructions.
Defective CCFL backlight, it may have the following symptom: Screen flashs on red/pink and off. Picture stays on in red and slowly be come normal. Picture flickering with dim display or appear black. Picture flickering on and off. All these symptoms indicate that the LCD backlight lamp (CCFL Lamp) has reached the end of the life and all you need to do is replacing the CCFL lamp.
Connect an external monitor to your laptop and power the monitor up first then the laptop, if you see the normal Windows images then the video card and laptop is OK and the problem is definitely the backlight. Dim image and/or dark display on the laptop's LCD screen indicates a faulty LCD backlight and it could be the inverter that supplies high voltage to the CCFL lamp or it is the CCLF lamp is nearly burnt out or burnt out, most likely this is the case.
The inverter can be replaced easily but the CCLF lamp is more time consuming and requires soldering skills.
Check out
www.lcdparts.net
for parts, repair service and DIY info

Sounds like a common problem as I found this article...
http://www.laptoprepair101.com/laptop/2007/01/31/replace-screen-inverter-fix-backlight/

http://www.laptopparts101.com/screen-inverter-board/

Your screen inverter is bad, or your backlight lamp. (The Backlight Lamp is a CCL. Cold Cathode Lamp. Resembles a very small, thin fluorescent bulb)

Info,
http://www.insidemylaptop.com/replace-screen-inverter-dell-latitude-d800-laptop/

How to replace an inverter in an Acer Aspire 4315? I can't find you the exact manual at the moment. HOWEVER, I can give you a link to manuals that are close to the Acer Aspire 4000 Series laptops.

I have found through the years, that many laptop makes and models, are very similar, when it comes to disassembly, of the entire laptop, or just the LCD screen. These manuals are for various models of Acer Aspire laptops,

http://www.notebook-manuals.com/manuals/ACER/Aspire
And,
http://repair4laptop.org/disassembly_acer.html

Look online for Screen Inverter and also Backlight Lamp, for your Acre Aspire. There are many places that sell them. (Average price for the lamp, ranges from $8.99 to $14.99, or so)

Backlight inverter is bad.

Mine does this too. It is the inverter. Of course it goes wrong as soon as your warranty expires. It can result from Best Buy sending you the incorrect battery and them insisting to put it in even though the voltage doesn't match...

You need to replace the inverter. This page should help:
http://www.insidemylaptop.com/remove-lcd-screen-replace-inverter-board-acer-aspire-5100-laptop/

If the screen appears dark with only a faint image or picture and the brightness can't be adjusted then it is likely that the screen backlight is not on - the backlight is like a very thin flourescent tube that runs along the bottom of the screen and provides the illumination. The backlight tube may be faulty or the small electronic inverter unit that powers the backlight tube may have failed. Occasionally the backlight is off because the little switch that is used to detect the screen lid being closed is broken or stuck in. If your backlight is faulty, some engineers will replace it - but it is more common that the entire screen is changed. If it is the inverter they can usually be replaced from ebay.