Hi,

how do I know if the ccfl backlight went bad or the inverter board gone bad in my 1525 Inspiron laptop?

when i boot up, the dell logo comes on bright, but when it goes to the windows sign on…the screen becomes very dark, i barely can see the windows logon..

I also tried an external moniter, that was successful …..so i at least know that my video card is ok….right??

I am hoping its a inverter problem, i find that easier to change

Any info , would be greatly appreciated

thanks
Mark NY  Mark(Quote)  (Reply)

Several cases come from inverter board for your reference:
1.Laptop boots up as usual but the screen blacks out after a while. There’s still an image on the screen, very dim. Or sometimes the screen lights back then goes off again.
2.The screen always shows black, the backlight cannot be lit up. However, people also can make out an image on the LCD.
3.In some cases, a buzzing noise comes from the inverter board location- the bottom  xiximoli(Quote)  (Reply)

I am having a problem which I thought it was the inverter. I replaced the inverter and the problem still shows up. The laptop boots up OK but then intermittently the backlight goes out. I thought it was a connection problem because sometimes when the lid is twisted slightly it would go out almost all the time from this. After changing the inverter I found that twisting the lid slightly does not always cause the backlight to go out. Sometime it can stay on for hours and other time after booting cold it will go off in minutes without touching it. I also suspected static from touching it but touching the lcd does not always make it go out. I was going to try and change the CCFL because as you stated above the image can still be seen very faintly when the backlight goes out. What do you think? Should I try another inverter board which I do not have or try the CCFL which I would also have to get.?
Thanks,
Steven  Steven(Quote)  (Reply)

It may be the problem of poor inverter interface connection, but not the CCFL.Reinstall the inverter or get a new inverter, that may be helpful. Related article, please read: http://www.yall.net/Laptop-LCD-Screen-Repair/dell-inverter-swap.html  mandyywl(Quote)  (Reply)

A while ago the screen on my Acer Aspire 9500 began to get dimmer and dimmer. Then it started going black a short while after booting up, and eventually it stayed black. If I reboot the computer or push the little button that shuts off the computer when you close the top, the screen will flicker dimly for less than a second, then go black again.

At first when this happened, I could still see an image behind the black screen if I shined a bright light on the screen. Now I can’t even see that.

I replaced the inverter board with a new one, but it didn’t help. I replaced the inverter board with another new one, but it still didn’t help.

Should I assume the problem is the LCD backlight and replace that next?

Thanks for your help!  Coastwizard(Quote)  (Reply)

You are right . It may be caused by the defective backlight lamp, replace a new one. The symptom would disappear.  mandyywl(Quote)  (Reply)

I have a Compaq NC6230, LCD brightness seems to be about 50% what it should be. Never flickers, just constant lower light. I’ve replaced 2 inverter boards. Looked alot better with LCD panel off but as I started to place panel back on it got dark again. Noticed the LCD panel has a small clear window at bottom that covers the ambient light sensor . Even when I remove it, and replace the panel with the open hole it gets 1/2 dark again.
Would you suspect backlight is just worn and needs replaced?
Also, when I disable the ambient light sensor with the function key,screen goes dim. But when i try to adjust manually with function keys, I get no adjustment whatsoev. Any way to fix/adjust that? Other function keys work fine.
Thanks for any help!
Kerry  Kerry(Quote)  (Reply)

It is the problem of backlight, replace a new one, the laptop may work well  mandyywl(Quote)  (Reply)

This is the problem that I got with my Toshiba Satellite M55-S329. Any suggestions on how I can fix this problem. Thanks in advance.

“Several cases come from inverter board for your reference:
1. Laptop boots up as usual but the screen blacks out after a while. There’s still an image on the screen, very dim. Or sometimes the screen lights back then goes off again.
2. The screen always shows black, the backlight cannot be lit up. However, people also can make out an image on the LCD.
3. In some cases, a buzzing noise comes from the inverter board location- the bottom”

“I am having a problem which I thought it was the inverter. I replaced the inverter and the problem still shows up. The laptop boots up OK but then intermittently the backlight goes out. I thought it was a connection problem because sometimes when the lid is moved slightly it would go out some time from this. After changing the inverter I found that moving the lid slightly does not always cause the backlight to go out. Sometime it can stay on for hours and other time after booting cold it will go off in minutes without touching it. I also suspected static from touching it but touching the LCD does not always make it go out. I was going to try and change the CCFL because as you stated above the image can still be seen very faintly when the backlight goes out. What do you think? Should I try another inverter board which I do not have or try the CCFL which I would also have to get?”

Thanks,
Homer  homer(Quote)  (Reply)

Another thing that I found out about my Laptop today was that when I close and open the screen the light comes back on for a couple of seconds maybe 10 seconds before it goes out again. After that I repeat the same process and it turn back on for a couple of seconds. Any suggestions? Thanks…  homer(Quote)  (Reply)

This problem sounds like a bad wire going from your motherboard to the inverter, given that you get a change in the results when opening/closing the screen. You should first try to disconnect the display connector from your motherboard, look for sings of corrosion, clean it, and reconnect. This connector is often under the keyboard behind an access panel. If that doesn’t work yuo could replace the wires. The wires often come in a taped bundle. You may be able to buy a replacement set of wires for your laptop model online somewhere.

It may be the ccfl or the wires to it, but a bad wire is most likely in my mind.

To purchase the right ccfl either look one up online for your model, or get the specs on your screen size and resolution (14″ XGA I think) and buy a ccfl bulb for that size / resolution. You may be able to find one on EBay for under $10.

Replacing the light involves dismantling the screen, so make sure youuo have an hour or more and a good clean workspace. There are some good videos online to guide you. Do a search on “laptop ccfl or backlight replacement”

Finally, as a last ditch, you may have a blown/failing display fuse. My Toshiba Portege display fuse failed and after replacing 2 inverters and a backlight I finally discovered this was the problem. The display fuse on my laptop was near the near the display connector on the motherboard it was small, white, and was labelled f5602 on the board, 3.15A. To test this, jump the fuse with the laptop off, turn it on and see if your screen lights up. To fix it, you will either have to get it replaced on the motherboard or if you are out of warranty and brave, you can rig up a wire or another fuse to bypass it.

Hope this helps.  Casey(Quote)  (Reply)

Casey, thank you for your long advice, vmt….  lang(Quote)  (Reply)

I just got finished replacing the CCFL backlight on my 2006 Macbook Pro 15.4. I’m not a hardware nut though I have built my own computer (not a laptop though). This process was nuts! It took me 6 hours and while the backlight now works it is now brighter at the bottom than at the top, so it’s not evenly distributed. I assume this is because of the step where it says “Note: Have a look at the screen base carefully before you remove the backlight lamp and reflector. Assembling the backlight and reflector back in place could be a very challenging task.” No kidding this could be a very challenging task! Next to impossible is more like it. The reflector was obviously not built to be taken off like that and then put back together. I had a crazy time trying to get the screens in the right order with the reflector in the right place. I thought I had it but apparently not as I still have the light distributed wrong. It would be nice if there was a screenshot or video somewhere of how the screen layers are supposed to go together with the reflector.

I highly recommend that unless you have done stuff like this before that you simply get a new screen. Of course even getting the old screen out is not a task for the weak hearted. The glue is much stronger than it says it is, I had to use a razor blade and it still took me over 15 minutes just to get it mostly separated from the casing which I still manages to bend a bit.

Good luck if you try to attempt this like myself.  David(Quote)  (Reply)

How do I what the wire orientation is? I no longer have the old lamp  elisabeth(Quote)  (Reply)

I Have a Sony Vaio PCG- FXA 59  elisabeth(Quote)  (Reply)