My LCD panel has gone blank! The laptop boots up fine, but the panel is blank
My Fujitsu Amilo M3438G LCD panel has gone blank! The laptop boots up fine, but the panel is blank. Upon close inspection, I can just about see the Windows XP login screen, although this is extremely faint. All is fine on an external monitor. I have noticed that pressing the Fn+F4 key combination to switch to an external monitor lights up the LCD for a fraction of a second. I assume this is a problem with the backlight not triggering when it is supposed to. I have taken the back off it but there is nothing obviously loose.
This has happened a few times in the past, but upon powering off then back on it has always sorted itself out. Oddly enough, in the past, it only seemed to happen when the power cable was connected but not turned on at the mains, although this could be a coincidence.
I have had this laptop for about 8 months (and so out of its 6-month warranty) and it stays at home, i.e. it does not travel!
I assume that the backlight itself is ok, since every time I press the Fn+F4 key combination it lights up, although briefly. As suggested here, I guessed it may be the ‘close-lid switch’ which has somehow got stuck in the closed position; however, I cannot find such a switch.
Just a quick update, I have now managed to take the LCD panel apart. I notice there are thin wires running vertically along the left and right sides of the panel (grey on the left, black on the right), connected to some small strips of metal. I wonder if this laptop uses a magnetic field to determine whether the lid has been closed as I cannot see a switch.
Could there be a problem here?
First of all I would like to mention two wires connected to small strips of metal you found inside the LCD panel. Most likely they are wireless card antennas and they have nothing to do with the backlight.
If you take a look at the generic notebook display assembly diagram, you’ll see that there are four parts that can cause the backlight failure: lid close switch, video cable, FL inverter board, CCFL (backlight bulb) itself. Let’s go through them one by one.
The video cable conducts data signal from the motherboard (video card) to the LCD screen and also provides power for the FL inverter board. I don’t think that you have a bad video cable because you still can see a faint image on the LCD screen and the backlight lights up for a second when you use Fn+F4 keys, so the power is coming to the FL inverter board.
I don’t think it’s the lid close switch issue because the backlight flashes sometimes. If it would be a stuck lid close switch, the backlight wouldn’t flash when you press Fn+F4.
Most likely it’s just a bad FL inverter board and you’ll fix the backlight issue if you replace the inverter. I guess it also could be a failed backlight bulb, but I would go with the inverter replacement first.
Here’s my suggestion. Open up the LCD panel again and reseat cables on both sides of the FL inverter board and the backlight still will not light up, replace the FL inverter board. Most likely that’s your problem.
Let me know how it goes.
July 8th, 2007 at 2:36 pm
My old Sony PCG-FX220 has been around the block for a few years about four years ago the screen went blank I called Sony and paid for one of there technician to walk me though a few things but nothing work so I took it into Greek Squad for repair, a thousand dollars later they told me that the motherboard had to be replaced it worked fine until one night about six months later I had left it plugged into 110 AC to charge the battery and in the middle of the night it exploded nothing seem to be hurt but the plastic case so I purchased a used case off of ebay from about four different sellers now the screen is blank again what could it be, before I forget I tried running the recovery cd’s but I cannot see the screen when I needed to push the keys on the keyboard and I also called Sony technical again they even remember me from so many years ago everything they told me to do I tried it, no luck (not even the reset button helped) I even changed the inverter out from the plastic screen case it came with the LCD screen case that I purchased off of ebay.
Thank you
Dan Paul Williams
341 County Road 134
Athens, Tennessee 37303
June 19th, 2007 at 7:33 pm
I have a Toshiba P15 series notebook. A week ago the screen went blank when I tap the keyboard to inactivate the screen saver. The computer worked fine when attach to an external monitor, and its still blank even when I try to switch between the desktop monitor and the LCD screen. The backlight of LCD screen still work as I can still control the brightness with the function key. Therefore, I think its not the inverter problem. I bought another video cable from ebay and it still doesn’t work. Is there a way to tell if the problem is really from the LCD screen itself without having to buy another LCD screen just to test it out? Your help will be greatly appreciated.
May 18th, 2007 at 11:56 am
last but not least,
so now you know that you cant rule anything out good luck
May 18th, 2007 at 11:54 am
again,
the bulb wiring is sealed in the lcd panel itself and can be tricky to locate, id like to think all my screen isues were inverter boards, but sometimes they are not, please be wary of the externall monitor method aswell due to the mobo on some laptops use a independent display adaptor which inturn doesnt condone the faulty adapter used by the lcd.
May 18th, 2007 at 11:48 am
hi,
if your inexperianced at fixing backlight bulbs please dont. can i just add that on some/most laptops i work with after replacing inverter boards at no success the next stage i consider would be to check the bulb wiring/ chaffing on metal case due to movement ive found this on most toshibas/ inturn leads to bulb renewal aswell a job not for the nervouse.
April 29th, 2007 at 7:37 am
Hello,
I have a Toshiba laptop…Satellite A105-S4201
All of a sudden screen is black, everything else seems to be running. Thanks, Kim
March 24th, 2007 at 1:38 pm
Hello, Laptop Freak:
Hope you could help me on this. I am using a Dell Latitutde D505 laptop computer. It boots up well, with the Windows sound coming out, but the LCD panel is very, very, very faint and dim. Whatever you think the problem is (faulty screen backlight and screen defective inverter board,failed motherboard, backlight lamp or tube, video harness), please give me a no-brainer step-by-step set of instructions. I appreciate your kind help to everyone!
March 5th, 2007 at 10:18 pm
Thanks fot the help so far…
I have tried to connect a screen to the dvi and even the tv output but nothing just the black screen on all 3 , (lcd,dvi,tv) and yes have tried to swap screens with the “F” key nohing happens … the only thing i know is that the machine boot`s up just fine starting windows normaly what i can hear on the sound of windows ….
you mention “video harness” ecxactly what and where is that ?? and where can i get one of theese ?
Best regards and hopefully i will find the help i need
)
Kindly
michael
March 5th, 2007 at 7:23 pm
Michael,
Attach an external monitor to the laptop and test the external video. If the laptop works fine with the external monitor and you can get video on it, probably there is nothing wrong with the graphics card. It’s still possible that you have a problem with the graphics card even though the external video works fine, but it’s not likely.
It tells me that there is nothing wrong with the backlight and screen inverter, because the screen lights up.
I think you might have a problem with the video harness or have a problem with the LCD screen.
I would try replacing the video harness first because it’s not as expensive as the LCD screen. It’s just a guess.
March 2nd, 2007 at 8:01 am
Hi there Laptop Freak…
I am also a owner of a fujitsu/siemens Amilo M3438G and my screen is in total black
… i have triede to reattach all caples (unless the one back on the screen will i try right away) .. it boots up just fine and starting windows can i hear on the sound of windows … but the screen stayes black… if i remove the gfx card inside (yes in this compputer the card is just a slot card) the monitor becomes white just fine so i guess it works just fine … any suggestions on what it could be ?? do you think the gfx card is dead ??
i have looked all over for a new gfx card (Geforce go 6800) but not found any cheap one
thanks in advance
michael
February 27th, 2007 at 8:28 pm
Steve,
Isn’t it still under warranty? I think you might have a faulty screen inverter.
February 27th, 2007 at 10:25 am
Folks,
Toshiba Satelite, year 2006: At first the laptop booted up normally. After about six months it still booted but when connected to the internet by cable or wireless, the screen went black although the computer itself continuted to function. A month later it started booting with the screen black. Now if I trick the computer into thinkin there is an external monitor, the screen comes back on and works normally until the machine is shut off. I use the Intel Graphics Acceleator program to set the computer for an external monitor. I had to learn the sequence of keystrokes to do it in the dark. The computer is useable this way, but it is a real bother.
Thanks
Steve
February 17th, 2007 at 10:48 am
Andy,
I think you might have a problem with the backlight lamp. I’ve published your questions and some suggestions here.
February 15th, 2007 at 5:57 pm
The laptop: Sony VAIO PCG-GRT100K
I have a client that is having problems with the display on their laptop. It is having the following symptoms:
***When the laptop is turned on the “VAIO” splash screen is flickering with a red tint.
***As soon as the “VAIO” splash screen goes away the backlight goes off.
***If I connect an external monitor the monitor shows the windows splash screen while windows is booting, but then as soon as windows comes to the “welcome” screen the external monitor turns off.
***When in Windows you can barely make out what is on the screen (backlight off)
***Once in windows hitting the “FN-F7″ button does not redirect the display to the external monitor.
***I don’t know if the laptop screen is doing what it is doing because of the backlight, or the inverter board. Or if this is a problem with the video “card” because it won’t go to the external monitor via the “FN-F7″ combo.
Please advise on how we can get this solved.
Andy Suarez
(847) 738-0249
andysuarez_at_realm249_dot_com
February 7th, 2007 at 7:03 pm
Randy,
I’ve never seen this kind of error before and have no idea what it means. This error mentions both the inverter and lamp, so I would assume it could be either of them. Probably I would try replacing the inverter board because it’s pretty easy and inverters are cheap. Here’s an example of replacing screen inverter on a Dell Latitude D610 notebook and here’s Dell’s instructions for Dell Inspiron 8600.
February 5th, 2007 at 9:03 pm
I have a Dell Inspiron 8600. Dim/Dark screen.
Error message LCD INVERTER LAMP NOT DETECTED.
Is this a backlight or an inverter issue?
Problem started a while back when after coming off of standby or hibernation while on battery the LCD would be dark and rebooting was necessary to bring it back up again. yesterday the screen was dim/dark on boot up and it hasn’t come back. Diagnostics via Dell support came uo with the error message LCD INVERTER LAMP NOT DETECTED
Dell support advises replacement of display assembly for more than computer is worth. I’d love to replace the inverter if that is the problem but how hard is this procedure?
advise wuld be much appreciated
thanks
February 4th, 2007 at 9:37 am
Dan,
In most cases you can fix a faint display by replacing inverter. In most cases but not all the time. Sometimes the same problem might occur because of a faulty backlight tube or bad motherboard. If you replaced the inverter board and it didn’t help, probably you have a failed backlight bulb or something else is wrong (bad motherboard, faulty cable, loose connection, etc…)
More advanced diagnostics steps are required to narrow down the problem. I usually connect my test backlight bulb and check if it lights up.
If you purchased a used inverter board, it’s possible you got a faulty one. If you have a lid close switch, make sure it’s not stuck inside and moves freely. When the lid close switch gets stuck inside, the laptop “thinks” the lid is closed and it cuts off power from the inverter board. As a result the backlight will not turn on even when the display is open.
February 3rd, 2007 at 6:51 pm
Thanks. Just following up and also seeking for any recommendation from you…
The SONY VGN-A170 LCD deassembly was easier than I expected. I just needed to take out four screws on each corner then carefully pull the cover off. The inverter is situated in the bottom middle just like the Toshiba. So, I bought an used unit from ebay and it got delivered today. Well… I replaced the unit, but the same result… very faint display on the LCD. Am I missing something or this unit is a faulty one that I need to return?
January 27th, 2007 at 10:10 pm
Dan,
I’m not sure where you can find instructions for Sony notebooks. Here’s a guide for taking apart display assembly on a Toshiba Satellite A65 notebook. Steps 1-6 shows how to access the inverter board. Probably your Sony laptop requires same disassembly steps.
January 27th, 2007 at 7:39 am
I have Sony VAIO laptop VGN-A170. Since three days ago, only very very very dim faint display on LCD (too dark to be even noticed) is visible, but the display to an external monitor is working. Based on the previous postings, I guess I have a FL inverter problem, right? If that is the case, I am looking for an instruction on how to replace a faulty FL inverter replacement on Sony VAIO VGN-A170. I could not find any in anywhere, incl’ Sony tech support site. Any help will be appreciated.
January 23rd, 2007 at 12:13 pm
Thanks Laptop Freak. I ordered a video cable online last night. After I get it in ill let you know how it is working. Thanks again!
January 22nd, 2007 at 5:24 pm
Jerry Jones,
You still can see an image on the external monitor, so most likely there is nothing wrong with the motherboard and the graphics card works fine. You cannot see any faint image on the LCD, so probably it’s not a faulty inverter board.
I would also try reseating the video cable on the back of the LCD screen. If it doesn’t help, I would try replacing the video cable next. You have a chance to fix the laptop and it’s much cheaper than replacing the screen.
January 22nd, 2007 at 4:42 pm
I took apart the xps m170 mentioned and reseated the video cable from the lcd to the motherboard. This did not help at all. Just to let you know there is no picture so i dont think it is the inverter because from what I have read if it is that there is a faint picture, I do not have even that. I tried to update drivers, and messed with the standby options. Nothing has worked so far. What step should I take first? I was figuring buying a video cable might be a good start or do you think that it is the entire LCD?
January 22nd, 2007 at 10:43 am
Hello, I have a dell xps m170 and I am having a problem with the monitor. I was playing some games last night and all of a sudden it went black but it was still on it did not turn completely off. The computer itself was also still on because I could hear the game sound. It did this twice last night and I let it set for around 20-30 mins and then it would work again. I figured it was due to overheating, but today I was just surfing the web and the laptop had been on for about 5 hours and then it did the same thing again. Now I have not gotten the screen to work. It has a glow but it is just black. I hooked up a normal monitor to it and it worked fine. I ran the diagnostics test and it found no problems but I do not know if that checks the lcd when I have it hooked up to another monitor. Any information would help .
January 17th, 2007 at 9:02 am
I found the solution. I ended up trying the FN F6 key which is the brightness control and the backlight came on. After rebooting, the screen would go dark again right after loading windows. I upgraded the bios and that fixed it.
Thanks for your help.
January 16th, 2007 at 7:54 pm
Bill Hannon,
Disconnect the external monitor and reboot the notebook. Take a closer look at the screen. Can you see a very faint image on the screen? It would be a regular image but very dim. If you can see it, most likely you have a bad FL inverter board. Open the display assembly and replace the screen inverter. Here are some inverter replacement examples.
January 16th, 2007 at 7:18 pm
Jack Carroll,
That’s weird. I know that it’s normal for the screen turn white (on Satellite M35X) when you unplug the video cable from the LCD, but I’m not really sure why the backlight goes off as soon as you plug the video cable back into the screen.
The screen is the same as the old one, right? I’m thinking if the screen is a little bit different it might have a compatibility issue with the old inverter.
With the old screen you were getting the image (with vertical stripes) and backlight at the same time, right? So I assume there is nothing wrong with the inverter board and video cable. May be your new screen is bad?
BTW, are you working on this laptop under warranty or it’s a cash unit? The laptop was purchased in the USA? You might be able to fix the laptop for free through Toshiba even though it’s not under warranty anymore, check out comments 7 and 8 in this thread. I hope it helps a bit.
January 16th, 2007 at 6:57 pm
Puck4001,
A few months ago I had to repair a Toshiba laptop with exactly the same problem. Man, I spent 2 hours playing with the power manager settings changing brightness for all power modes back and forth and it didn’t help. The BIOS didn’t have any settings for that either (some laptops have it in BIOS). I even installed a test hard drive and reimaged it with the factory restore CD but it didn’t help either. Finally I had to replace the motherboard, fortunately for my customer the unit still was under warranty.
If you don’t have any settings for brightness in BIOS or power manager software, you might have a problem with the motherboard. I hope not, but it’s possible.
I would probably try reflashing/upgrading the BIOS just in case. Please let me know if you find a solution for this problem. Good luck!
January 16th, 2007 at 5:29 am
I have Toshiba Satellite P35-S609, and I also have a backlight problem. The screen has now gone black and I am using the computer with and external keyboard and monitor.
Is there a solution to this problem, please advise
Thank you,
Bill Hannon
January 15th, 2007 at 7:30 pm
I have replaced the display in a Toshiba Satellite M35x. The screen had rainbow verticle stripes in it so I took it out and got the serial number off of the display and ordered a new replacement. When the red and white wires are plugged into the right side of the inverter board the backlight comes on and I get a white screen. When I connect the video cable to the back of the display the monitor is dark although I can see the image is all there if I look at it under a light. What would cause the backlight to go off when connecting the video cable?
Thanks,
Jack