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.
January 15th, 2007 at 7:04 pm
Hi there
I have a compaq r4000 with windows xp pro 2002.
My problem that has only just happened is that when the power cable is IN the the screen becomes DARK, when the power cable is out the screen becomes LIGHT. I assume you can see the fail in logic there. its very annoying when im photo editing.
I have gone into power manager but there is no option to amend this.
there is also no way to amend this in my bios.
thanks for any help
January 12th, 2007 at 3:01 am
The solution at the top of this page thankfully worked fine on my Fujitsu Siemens L7300 (intermittent and finally total loss of power to the backlight – apart from when the screen is lowered to activate the switch, when it still briefly flashed power to the screen). Replaced the inverter and with just a little care taken removing the outer edge of the screen cover all’s good.
Good tip: To eliminate whether the problem is a faulty connection in the cabling is to keep the screen still and use a bit of paper to activate the screen switch (located just back from the power switch under the LCD) If its flickers when touched then it isn’t a connection/cable problem.
Thanks for your help!
December 20th, 2006 at 2:01 pm
I have a Fujitsu LifeBook S-2010 laptop with the same situation as the Fujitsu Amilo above. The screen is really dark, boots up and can be viewed on an alternate monitor.
I took off the lcd mask and reseated both cables on each side of the FL inverter board, with no luck. Can you tell me where I can go to purchase an inverter board(used if possible)for my particular model or if there is a compatible board for my model. I’ve looked everywhere and the only prices I have found were over $200.00. Any advice or info would would be greatly appreciated!
Thanks,
Leslie
December 16th, 2006 at 7:32 am
Sammy,
It’s possible that you have a loose video cable. First of all, I would try reseating the video cable on the back of the LCD screen, it might help. I don’t have instructions for Tecra A2 but I have them for Tecra A3, they should be about the same. The video cable is pictured on the step 5. The connector is located under the yellow tape and when the connector is not seated properly, you might get a white screen. If the laptop is still under warranty do not open it, send it for repair to Toshiba or take it to a local service center.
December 16th, 2006 at 7:23 am
Alison,
It’s a hardware issue, most likely you have a faulty screen inverter. There is nothing you can do without taking the laptop apart.
December 16th, 2006 at 7:18 am
Mark Burgos,
I don’t have instructions for replacing a screen inverter on HP Compaq laptops and I know that you will not find them on HP website either. I’ve created a few disassembly guides for Toshiba laptops and some of them show how to replace the inverter board. Read through my LCD disassembly guides and you’ll see how to access and replace the inverter. There shouldn’t be a lot of difference between HP and Toshiba laptops, they all have similar disassembly steps.
December 15th, 2006 at 6:05 am
Hi trying to troubleshoot a tecra a2 video problem. The screen is constantly white but when you bend the laptops chasis it fixes itself until u release it to the normal position and then the screen goes white again.. any ideas will be helpful
December 15th, 2006 at 1:48 am
my laptop has also gone completely black, i can faintly see the icons and it loads up fine,.. Is there anything i can do without taking it apart? thanks in advance
alison
December 14th, 2006 at 9:17 pm
Sir please post a instruction how to replace Hp compaq invterter.. Thank You So much Sir…
December 8th, 2006 at 2:12 pm
I have an interesting issue. When I open and close the panel for my laptop the LCD flickers on and off. Occassionally if I stop it will remain off and by moving the panel back and forth I can get it to turn on. This problem was preceded by the battery and power lights, which are on the base of the LCD display, flickering on and off as well.
Thanks in advance,
Eric
December 7th, 2006 at 5:46 pm
I want to know if my Toshiba laptop 1135-S125 satellite is backlit or if it has lighting from the top, bottom or sides? If it’s backlit, is there a protechive film covering the back of the screen keeping the light from coming thru the back? I want to mod my laptop lid. Im thinking of cutting small holes or slots in it for what I want to do. I’d like to let the light from the screen shine thru these holes or slots. Is this possiable?
Thank you.
December 5th, 2006 at 10:46 pm
Philip,
You said that the screen flashes when you tap on the lid close switch. Most likely there is nothing wrong with the switch and you have a failed inverter board. I would try replacing the inverter first. Here’s an example on how to take apart the display assembly and replace the LCD inverter. The inverter is shown on the step 7.
December 3rd, 2006 at 8:01 pm
I have a Toshiba Satellite 1955-S801. It works fine when i use an external monitor and i have taken it completely apart and reseated every possible cable. I’m 99.99 % sure its the lid close switch. The screen flashes when i tap on the switch, but it doesn’t stay.
My question is, how do you properly clean it, or is there someway to bypass it?
Thanks in advance,
Philip Hayden
December 2nd, 2006 at 8:49 pm
Jesper,
It sounds to me lake a bad inverter but you cannot be 100% sure until you run the laptop with a test inverter. How much time you have to return the laptop? You can buy one really cheap on eBay but it’ll take some time for shipping.
December 2nd, 2006 at 6:59 am
Hi there,
Very usefull site – keep up the excellent work!
I just bought a 2nd hand T30 and the backlight dies periodically. I think I have isolated it to the inverter but since the seller can still take it back I need to be (almost) sure it is not the bulb it self. Since I ot the T30 at a pretty good price I’d like to keep it if it is inly the inverter that needs to be exchanged.
I can now reproduce the error by turning up the LCD to max level, shortly after it goes out. Turning of the screen with FN+F3 and waking it up again turns on backlight again and if I dim the screen a little bit it stays on, no problems.
My question, can I be sure this is the inverter or could a failing bulb show similar behaviour?
Cheers!
Greetings from Denmark
November 30th, 2006 at 5:13 pm
Hey Lee,
Did you buy a used inverter, may be it was a defective part? I would try replacing it again. The screen worked fine for 15 minutes after the first replacement, so I assume that the backlight, video cable and motherboard is fine.
November 29th, 2006 at 4:46 am
Hi,
I have a Fujitsu-Siemens Amilo M1450G. The screen was dim so we replaced the inverter. The screen then worked for about 15mins but has now gone back to not lighting up the CCFL…
We have buzzed out the LCD cable, checked & reseated all cables and associated connections etc..
Any ideas as to what the prob could be?
Thanks in advance for your help.
Lee
Cool website by the way
November 28th, 2006 at 5:29 pm
Brad Sherman,
May be you have to choose a primary monitor in the BIOS setup? Enter the setup and see if you can see any settings for the display.
I think another way (as an emergency) would be unplugging the LCD video cable from the motherboard.
November 28th, 2006 at 11:16 am
Chris Killion,
The backlight bulb is located inside the LCD screen and to replace the bulb it’s necessary to take apart the screen. I know that it’s possible but I’ve never done it myself. Toshiba lists two different FL tubs for Satellite A15 with the following part numbers: P000371180 (for 15” Samsung screen) and P000371040 (for 15” Sharp screen). I don’t know what the difference is and if these backlight bulbs are interchangeable but if you search on Google by the part number you can find a seller. I would recommend contacting the seller before you buy the backlight bulb, just to make sure that’s the part you are looking for.
November 27th, 2006 at 6:23 pm
I currently have a failed backlight and am attempting to connect an external monitor. During startup the external monitor works and you can toggle between the two using Fn+F4. Once windows logs in though, the external monitor stops working. The screen is extremely faint, but given enough patience I can still navigate around. When I go into the display settings it does not give the option to select another monitor. The toggle key is unable to bring up the external monitor as well. Any suggestions on what I can do to remedy this problem? I’m currently more concerned with getting the external display working as opposed to getting the lcd fixed. Thanks.
November 26th, 2006 at 5:43 pm
Have a 3 yo Toshiba Satellite A15-S127. Display does not light-up. Can see Windows desktop images faintly by shining flashlight on the screen. Repair shop swapped out the inverter, but problem persists. Diagnosis: backlight failure. Is it possible to replace the backlight rather than the whole LCD? If so, where can I find the part? Cheers. CK
November 25th, 2006 at 9:44 pm
Bruce,
Here’s a generic notebook assembly diagram. It will help you to understand what the FL inverter is. I work mostly with Toshiba laptops and can show you how to access a failed inverter on a Toshiba laptop example. I don’t think it would be much different for Fujitsu laptops. Here’s a website I dedicated to Toshiba laptop disassembly. Read through a few display disassembly guides and you’ll see how to get inside the laptop display.
November 25th, 2006 at 9:30 pm
Kendi,
I think you have a failed FL inverter board, the part that works as a power supply for the backlight bulb. The FL inverter board is located inside the display assembly and could be replaced if you remove the LCD mask.
November 24th, 2006 at 3:33 pm
I have a Fujitsu N Series Lifebook that cost me a bunch. Just about a year after I bought it, my screen failed to come on. I could see it very faintly in dark light. Also, I could access the computer with another monitor. During the transfer to the external monitor, I would get a brief flash on the laptop screen showing the working screen, just before it appeared on the external monitor, much like Paul’s problem above. Fujitsu said they would remedy the problem, even after the warranty expired, but I was too busy to send my laptop to them. Way too much time has now passed, so I do not plan to ask them again.
But I was extremely happy to learn of the inverter, although I do not know what one is. I can build a desktop with no trouble, but I never messed with laptops. Can you give me a bit more information on the inverter and what the repair entails? Thanks, I am sure there are a bunch of Fujitsus with this problem. Also, any remedy for the supersensative keyboard? Jumps all over the place while I type.
November 22nd, 2006 at 6:31 pm
I have a Toshiba M35X-S114 out of warranty which has not been dropped or jolted but has traveled under 10 times to the local Panera Bread for surfing. The problem is that today after a short trip out (I left it on but nobody was there to touch it or anything) I returned to find the screen black. After the shock wore off I removed the battery, unplugged and restarted it and noticed that I could see faint images in the background. After connecting an external monitor the display began working again. I detached the external monitor and it went black BUT after I clicked the lid close switch a few time it was on again of again intermittently. When I tried to access the internet it went blank again. After adding the external monitor it stays on without fail. What is wrong? Please help.
November 20th, 2006 at 12:53 am
Hi, whe replace mi ccfl bulb the panel works great for 2 o 3 days , now , whge start , the bubl goes on for 2 or 3 second and goes off….i try to replace conecctions and so many thing ….but the problem contiinue … its possible , the inverter board has dead with the new ccfl bubl?
any ideas?
Thanks
Waldo
Sorry for my prehistoric english…..
November 13th, 2006 at 11:17 pm
Eli,
Connect the laptop to an external monitor and set up the laptop to output video on both screens at the same time.
If the laptop LCD fails but the external monitor works fine, then most likely you have a bad LCD screen.
If both screens fail at the same time, then it’s the video card problem. The video card in this model integrated into the system board. If the video card goes bad, the entire system board must be replaced.
November 13th, 2006 at 3:38 pm
I purchased my Toshiba Satellite 1135-S125 from a friend. He told me that it had an issue with the screen. Sometimes when you turn it on the screen is grey (the laptop still boots up fine). You have to turn it on and off a few times and shake it around a little for it to start working. So I figured the problem was with the LCD flex cable. So I opened it up, but the cable was firmly seated. I still tried replacing the cable, but that didn’t work either. When I would connect the laptop to an external monitor the picture would show up fine on it. The symptoms on the laptop started to get worse. The grey screens started to get more frequent. Then the screen turned white instead of grey. Now sometimes the screen stays blank when I turn it on. And sometimes the screen turns on but the backlight doesn’t work. I figured the problem was with the inverter board so I replaced that. Still the back light remains off. I can’t seem to figure out the problem with this one. I opened up the laptop everything is seated well. If its not a cable then why did the shaking make any difference? Thank you for any help, Eli Teigman
October 28th, 2006 at 4:14 pm
Well, thanks for your help, and, I can happily say that my laptop is now fixed. It was, as you suggested, a faulty Inverter. I bought a new one for £5 ( 7.5 euros, 9.5 US Dollars) and hey presto!
So, once again, thanks for your help, this time last week I had never even heard of an Inverter ! Now, with your guidance, I have fitted a new one and bought a spare also, and all is well.
If anybody has trouble sourcing parts, inverters etc, especially for Fujitsu Siemens hardware, you could try here: http://www.servicesource.co.uk/default.htm
Cheers
Paul
October 23rd, 2006 at 2:59 pm
Thanks for the response. I’m sure you are totally correct about those wires running either side of the panel, makes perfect sense.
It would be great to be able to prove it was the inverter without buying one! I did take a quick look on ebay but it came back blank (like my panel!). Maybe the inverter board itself has a part code on it so I can purchase one.
Cheers
Paul