Question about Dell Latitude C640 Notebook

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Lcd screen problems

When i turn the laptop on the screen apeers as if the backlights are out of it.when i removed the lcd screen from the computer a soldered wireing ribbon is detached on the upper right corner of the lcd.i think this is a tab weld but im not sure.when i hold the peice on and line up the welds the backlights still do not work.

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That is repairable and I'm sure thats the problem

Posted on Jan 19, 2009

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Why are all the lights on LCD screen on?


How to troubleshoot and fix video problems
Here are some tips and tricks for troubleshooting and fixing laptop video problems. Video issues are very common within portable computers and with the following tips you should be able to detect and eliminate basic laptop video problems.
Laptop LCD screen has a faint image.


all-lights-lcd-screen-4ztirbadqll2ypvmakqp10pq-2-0.jpg
Look at the LCD screen very closely and check if you can see a faint image on the screen. It's possible that the LCD lid close switch stuck in the "closed" position and the backlight stays off even when you open the LCD screen or turn on the laptop. The switch turns off the backlight when you close the LCD display to save the laptop battery power. Check the LCD lid close switch. Usually it is a small plastic pin located close to the LCD hinges. Try to tap on the switch a few times to turn on the backlight. If after tapping on the LCD lid close switch the backlight stays on, you fixed the problem.
It is also possible that after tapping on the LCD lid close switch the backlight works fine, you see a normal video on the screen for some time and then the backlight turns itself off again. In this case I would blame the FL inverter board. Try to reseat cables on both end of the FL inverter to make a better contact between the cables and the FL inverter board. If it doesn't help I would try to replace the FL inverter board.
Laptop LCD screen is solid white color.


http://www.laptoprepair101.com/wp-images/white-screen/1-laptop-white-screen.jpg
Most likely it is just a bad connection between the LCD display and the system board. I would try reseating the video cable connector on the back of the LCD screen first and check if it fixes the problem. After that I would try reseating the video cable connector on the system board. I would also try reseating cables if there is no video on the LCD screen at all.

http://www.laptoprepair101.com/wp-images/bad-laptop-video/washed-lcd-image-1.jpg
Try to connect the LCD screen to an external monitor. If the external video is fine, you have a problem with the LCD screen or the LCD video cable. You can try to fix the problem by reseating the video cable on the back of the LCD and on the system board.
If you see the same garbled video output on the external monitor most likely it is not the LCD screen problem. In this case the system board (with onboard video) is bad or the video card is bad.
REFERENCE: http://www.laptoprepair101.com/troubleshoot-fix-laptop-video-problems/
GOOD LUCK.

Jun 30, 2015 | PC Laptops

1 Answer

LCD screen flickering


Display Configuration A flickering screen may be caused by the computer detecting incorrect display settings as it starts or returns from sleep. It can also come from changes to the screen resolution settings caused by a new program or update installation. Verify screen resolution before assuming the issue is hardware related. Faulty Inverter Next to the display screen behind the plastic screen bezel is a small component called the inverter, which supplies power to the screen backlight. The flickering indicates the power is not reaching the backlight. To fix the issue, replace the inverter. Faulty Connectors The wires and cables traveling from the display around the hinges and into the motherboard tend to wear at the hinge area. Over time, the opening and closing of the screen causes this wear. The solution is to disassemble the plastic casing of the laptop, reorganize the cables so they have no interference from hinges, or replace the cables and connectors with new ones made specifically for the computer make and model experiencing the issue. b> Test an LCD Inverter An inverter is an electrical device on the bottom of your laptop screen. The job of the inverter is to convert DC electrical current to AC voltage to maintain power to the backlight lamp. If the display on your laptop is dark but working, odds are the inverter or the lamp are at fault. When troubleshooting monitor problems on a laptop, you may need to evaluate the inverter to determine which of the two parts is malfunctioning.

Remove the screen bezel on your laptop. The bezel is the piece of the computer casing that surrounds and protects the LCD screen. To remove the bezel, remove the screws around the screen. Bezel removal method may vary by model. Once the screws come out, the bezel should pop off. The inverter will be under the screen. Attach the positive probe (+) of a multimeter to the pin 1 on the inverter. The inverter has two connections, one on each end. With the laptop screen facing you, look at the left side of the inverter. Pin 1 is the top metal flange pointing to the right. Secure the negative probe (-) of the multimeter to any bare screw. There should be a screw securing the inverter to the laptop that will be perfect for the negative ground connection. Turn the laptop on to test the inverter. Turn the multimeter on and check the multimeter reading. If the display records voltage going to the inverter, such as 19 V DC, the inverter power supply is working. Turn the laptop off. Unplug the LCD inverter connection on the right side of the inverter. This disconnects the backlight from the inverter. Plug a working backlight to the connection on the right side of the inverter. Turn on the laptop. If the screen lights up, the backlight lamp is bad but the inverter works. If the screen remains dark, the inverter is bad.

Feb 25, 2013 | HP Pavilion PC Laptops

1 Answer

LCD backlight replacement


If the LCD screen on your IBM laptop is going dim, chances are the backlight is breaking down. The good news is that if you don't want to spend the money to have a technician replace it, you can do it yourself. There's no need to open up the main body of the computer, but you will have to get into the screen to do the work. Here's how.

Power off your IBM and remove the battery. Remove the nine screws (three on each side) on the side of the screen. Once the screws are removed, the plastic bezel (screen guard) can be removed. Pop the bezel out, exposing all of the LCD screen. Pull the LCD screen gently away from the computer by the corner. Be mindful that the screen is still connected to the computer by a ribbon cable. Remove the tape over the ribbon cable where it connects to the screen and gently pull the cable to disconnect it. Turn the LCD facedown, and remove the piece of tape that holds the top metallic foil against the back of the LCD. Lift the metallic foil to expose the backlight. Remove the single screw at the end of it that holds it in place. Unclip the wire at the end of the backlight from the inverter (power source to the backlight), and remove it from the LCD. Replace it with the new backlight (available at any electronics store or online). Be sure the new backlight is compatible with your particular IBM model. Reassemble the computer reversing the order in which you took it apart.

Remontage / reassembly Lenovo Thinkpad T60 ou T61 all versions http://www.youtube.com/watch?v=dxNB3sxUfos ThinkPad Back Light Replacement http://www.youtube.com/watch?v=tr_trXGEYT4 IBM lenovo T61 display problem http://www.youtube.com/watch?v=Em6XBA_nOZ4


Feb 05, 2013 | IBM Lenovo ThinkPad T61 Notebook

2 Answers

It looks like the bulb in the screen is burnt out. The screen is completely dark when fully chared.


You can determine if the bulb is bad by simply connect a monitor to the fifteen pin AGP port located at the side of your computer usually color blue. If your computer display the desktop on the monitor,you should change the bulb in your computer display.To change the backlight you need to follow these steps :Power off your Toshiba laptop and make sure the AC adapter is unplugged.
Remove the screws on the side of your laptop screen. Once the screws are removed, you can remove the plastic bezel (screen guard).
Pop the bezel out, exposing all of the LCD screen. Pull the LCD screen gently away from the computer by the corner. Be mindful that the screen is still connected to the computer by a ribbon cable.
Remove the tape over the ribbon cable where it connects to the screen, and gently pull the cable to disconnect it.
Turn the LCD face down, and remove the piece of tape that holds the top metallic foil against the back of the LCD.
Lift the metallic foil to expose the backlight. Remove the single screw at the end of it that holds it in place. Unclip the wire at the end of the backlight from the inverter (power source to the backlight), and remove it from the LCD. Replace it with the new backlight (available at any electronics store or online), and reassemble the device the same way you took it apart.

Aug 30, 2010 | Toshiba Satellite A105 Notebook

1 Answer

Acer Aspire 5100 Laptop Screen Works Intermittently


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/

Apr 06, 2010 | Acer Aspire 5100 Notebook

1 Answer

Acer aspirw 5100 brightness


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.

Dec 28, 2009 | Acer Aspire 5100 Notebook

3 Answers

My screen is dark when the computer logs on (but I


Fn+F1 Decreases the display brightness. Fn+F2 Increases the display brightness.

Sep 24, 2009 | HP Compaq nx9030 Notebook

2 Answers

Acer 5810t laptop. screen gone black


Press and hold the Power button for 45 seconds to turn the laptop off.

Then, remove the battery from the battery compartment and clean the metal contacts.
Next, reinsert the Battery and try to turn it ON.

If the display still doesn't come then you may try connecting an external display to check if the Computer is able to produce display and the issue is with the backlight of the LCD screen.


wish u good luck!!!!!!!!!!!

Sep 17, 2009 | PC Laptops

2 Answers

I turn on my computer but the screen is still black


think you might have a failed screen inverter (FL inverter); this problem is very common with laptops. The inverter board acts as a power supply for the LCD screen backlight bulb, it converts low voltage DC power into high voltage AC. On most laptops the inverter board is located inside the display assembly below the LCD screen and you can get access to it if you remove the screen bezel (LCD mask). When the screen inverter goes bad the backlight will not turn on anymore or it turns on for a short time and then goes off, but you still can see a faint image on the screen and the external monitor works just fine. First of all I would make sure it’s not just a loose connection and reseat connectors on the inverter (it looks like you already done this part). Next, I would try replacing the inverter board. It might fix your problem with the backlight. It’s possible that you have a faulty cable, bad motherboard or even bad LCD screen, but I would try replacing the screen inverter first.

Oct 06, 2008 | Toshiba Satellite Pro 4600 Notebook

1 Answer

Screen


Plug an external monitor if it goes you have LCD problems

Sep 23, 2007 | Getac W130, High Bright Touch Screen XGA...

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