No lcd inverter in cq56 how come

Sounds like your LCD backlight unit needs to be replaced.
The part is cheap but you will need to open up the LCD screen and replace the CCFL tube

http://www.ebay.com/itm/CCFL-Backlight-Wire-Harness-Compaq-Presario-CQ56-124CA-CQ56-148CA-CQ60-419WM-/181084672480?pt=LH_DefaultDomain_0&hash=item2a297cd1e0

You have a flew tab issue ( where the circuitry attaches to the screen) which is located under the screens top frame section. Or there could be a blown resistor or didode on the small board the flex tab attaches to also underneath the top frame section of the screen assembly

The problem is caused by the inverter board, "just below the screen" is more than likely the problem, or it is the backlight behind the LCD display, "built in" less likely.

Hook a external monitor to the video output usually on the back, if okay! the inverter board or the backlight behind the LCD has failed. But if symptoms are the same, it means the video graphics card is defective normally built into the motherboard.

The LCD screen for the Advent 7102 does not produce light. It needs an additional light source.
A Backlight is the additional light source.

A Backlight is a CCFL.
Cold Cathode Fluorescent Lamp
Similar to Fluorescent lighting used in homes, and businesses, but on a MUCH smaller scale.

An Inverter (Screen Inverter) converts electricity from the laptop, for the LCD screen, and the Backlight.

90 PERCENT OF THE TIME the fault is the Inverter.


The Inverter is a small circuit board located behind the Display Bezel, and under the LCD screen.

[ The Display Bezel is the thin plastic frame in front of the LCD screen. Resembles a picture frame ]

Example of a screen Inverter for an Advent 7102 Netbook PC,

http://www.laptoppowerjacks.co.uk/category-27/Acer12.html


Regards,
joecoolvette

Hook a spare monitor to the video output on the back of the laptop, if okay it means the video card is working fine. The problem is a bad inverter board, "located under the LCD display" or the back light is defective behind the screen, "usually means a screen replacement"

The most likely problem in this situation is that the inverter is burned out. Do you hear sound? If your computer boots and there is sound, it is definitely the inverter board. You might want to try to replace the inverter board. I think it's about $15 on ebay. If you are tech-savvy you can take the computer apart. The inverter is usually located below the LCD screen. for more info on replacing the inverter click here http://www.insidemylaptop.com/remove-lcd-screen-inverter-board-hp-pavilion-dv9000-laptop/

You have 1 of 2 issues...

1.) You have a Bad LCD Bulb.. You can get a replacement LCD Bulb and change the LCD Bulb inside the Display which is cheaper and easier than replacing the whole backlight panel.... LCD bulbs cost around $12 Be careful these bulbs are Fragile and if bent when installing- will break...

2.) You have a failing Power Inverter... this is located just under the screen display panel,, it is a circuit board that the screens lcd bulb plugs into and the display cable plugs into... this inverter board converts the DC power in the laptop back to AC power because the screen needs more power to power the lcd bulb...

Your Problem Is One of These 2 Things... Your Best Bet Is To Test The Power Inverter First - Since It Is The Easier Of The 2 To Replace/Repair

Your inverter board is OK otherwise you will not get any light on the screen, there is only one inverter board, Check the flat ribbon cable connected to the LCD panel (locate behind the LCD panel), when this connector comes off you will get white screen.