Screen inverter board
Laptop inverter boards (also know as LCD inverter, FL inverter, screen inverter, backlight inverter) come in different shapes and sizes. On the picture above you see some typical looking inverter boards found in laptop computers.
The inverter board works as a power supply for the backlight lamp mounted inside the LCD screen. The inverter board converts low voltage DC power (few volts) supplied by the motherboard to high voltage AC power (few hundred volts) needed for the backlight lamp.
When the inverter board works properly, the backlight lamp gets power and the LCD screen lights up. As a result, the image on the screen is bright.
HOW INVERTER CONNECTED TO LDC SCREEN
On the picture below you can see a typical laptop display assembly which includes the LCD screen, video cable and inverter board.
One side of the inverter board connects to the backlight lamp and another side to the video cable (LCD screen cable).
HOW INVERTER MOUNTED INSIDE LAPTOP DISPLAY PANEL
In most laptops the inverter board is mounted below the LCD screen as it shown on the picture below. You can get an access to the inverter board when you remove the screen bezel – a plastic frame around the LCD screen.
TYPICAL INVERTER FAILURE SYMPTOMS
Usually inverters fail in one of the following ways:
1. When you turn on the laptop, the screen lights up for a short period of time and then goes dark. You still can see an image but it is very dark, almost invisible and definitely not usable. When you restart the laptop, the screen lights up and then goes dark again. The laptop works fine with an external monitor.
2. Your laptop turns on but the screen remains dark all the time. You still can see a very dim image outline. The laptop works fine with an external monitor.
3. The laptop screen works fine for hours or even days, but sometimes it goes very dark as it mentioned above. When you restart the laptop, the screen works fine again.
Inverter failure symptoms are very similar to backlight lamp failure symptoms and in most cases you cannot tell which one is causing the problem until you replace either the inverter board or the backlight lamp. From my personal experience, inverter boards fail more often than backlight lamps. If you have to guess, replace the inverter first.
June 21st, 2010 at 9:45 pm
JLVivian,
What is the full laptop model number? HP G60-XXXXX?
The model number is printed on the bottom sticker.
June 21st, 2010 at 9:33 pm
Ferdinand,
Most likely it happens because you are using a wrong inverter, it doesn’t provide correct voltage for the backlight lamp. I would try installing the right inverter.
June 21st, 2010 at 11:58 am
Hello there,
First of all thanks a lot for this useful site!
I need help!
I have a Sony Vaio VGN-FZ31J Laptop and had just the problem described here (display went dim, sometimes bright then dim again).
I exchanged the inverter for one from an older Vaio Laptop (model: PCG-K215B) that I had.
NOW: the backlight is working constantly but is much much dimmer.
Sometimes it becomes brighter (as bright as it should be) for a second but then becomes dim again.
ALSO: I cannot control the brightness anymore, not by using the Fn/F6 keys, neither by going into the battery/brightness settings. That is: I can increase or decrese the brightness settings but it has no effect whatsoever.
Is the inverter not up to the task of running with my newer vaio model? But why does it work sometimes then? Please tell me what I should do.
June 17th, 2010 at 11:30 am
Which is the part number of the Screen Inverter of the HP G60??
June 16th, 2010 at 7:57 pm
Hi,
Great website! I need help. I dropped my Sony Vaio and cracked the screen. I took it in to diagnose how bad the damage was and they said that everything was fine except for the screen. I ordered a screen and installed it and it is still black. The screen is black but I can see two faint large black vertical bars and can also see the windows logo in the background–just shades of dark black. When hooked up to an external screen it works fine. What is the most likely next thing to replace–the inverter, video cable or something else??? It was dropped very hard…
June 11th, 2010 at 3:10 pm
Hey, I have a Compaq Presario V6000. The screen has gone black although at an angle can still see the desktop, also external monitor works fine. I was suspecting the inverter so replaced the inverter but still have the same problem however I am concerned that maybe the replacement inverter is faulty also. When the laptop powers up there is a buzzing noise and flashes (sometimes also burning smell) from bottom right of LCD like the backlight is trying to come on but fails. Is my problem likely to be the backlight bulb itself rather than the inverter ?
Thanks
June 11th, 2010 at 6:58 am
shai,
Is it very dark? No backlight at all but the image is still on the screen?
Try replacing the inverter board first. It’s located inside the display panel and mounted below the screen.
If replacing inverter doesn’t help, you’ll have to replace the screen.
June 11th, 2010 at 6:35 am
I have an HP Pavilion dv4. It used to work perfectly until the screen just went dark, sort of a “negative” film. what do i do? I badly need my laptop for work. Help needed very very badly.
May 23rd, 2010 at 12:37 am
i have a compaq presario v 6000. probably it has an fl inverter problem , but do i have to change the full lcd!!!
May 3rd, 2010 at 7:27 pm
HP dv6000 GETTING FOUR SMALL SCREEN, PLEASE HELP
I have a HP dv6000 laptop, every time a turn it on I get four small screens about 4″x5″ each. This happens as soon as the BIOS screen appears and it stays like that even after windows loads up. Right now it is basically useless since the fonts are too small to be read. I have checked almost all the post on this page and does not look like an inverter problem. Do I have to change the screen? But again all I know is what I have read on this great site. Any help would be greatly appreciated.
I updated video driver and did not help
May 2nd, 2010 at 7:33 pm
Update to my previous post #268
The screen does exact same thing (barely visible) even when I disconnect the fl inverter board. Brighter screen function (fn + f8) didn’t help. I can see a normal desktop screen through the projector screen when connecting.
May 2nd, 2010 at 7:25 pm
I have a Compaq Presario A900. The screen image is somewhat visible but not enough light to operate (can’t figure out the mouse). Can you suggest me if this is the issue of fl inverter board or the back light lamp or something else. I am thinking about buying the fl converter board but the article says ‘the screen lights up for a short period of time and then goes dark’.
Thanks for your suggestion in advance.
martin
May 2nd, 2010 at 11:03 am
My screen recently has decided to work when it feels like it. Power cycling the screen works after a few attempts. When it doesn’t work, the screen still lights up but the screen has narrow vertical bars of color instead of the correct image. External display works fine even in clone mode.
http://img714.imageshack.us/i/04302010.jpg/
http://img218.imageshack.us/i/04302010004n.jpg/
I have disassembled the screen and checked all cables. Firmly reattached all cables and closed bezel. The display works but a few power cycles later, it is back to where I started.
April 27th, 2010 at 5:04 pm
thanks so much i have been researching on LCD problems and have never found a solution….i have now and its thanks to laptopparts101.com….
cheers to this wonderful website
April 26th, 2010 at 8:02 am
Helpless,
Apparently you damaged the LCD screen. You’ll have to replace the screen.
April 26th, 2010 at 7:29 am
I dropped my Toshiba Laptop. The only seemingly problem i found is that the right half of my screen is black and gray. Does anyone know what could be wrong?
April 23rd, 2010 at 7:55 am
senaville,
Could be bad hard drive or memory.
This is an HP laptop and most likely it has the hard drive test utility in the BIOS menu.
Turn on the laptop, enter the BIOS setup menu and find the hard drive diagnostics utility. Run this utility. If the hard drive fails test, you’ll have to replace it with a new one.
Some HP laptops also have memory diagnostic utility in the BIOS menu. Test memory. Alternatively, you can use Memtest86+. If memory fails test, replace it.
April 22nd, 2010 at 8:20 am
Hello,
I tried to install windows xp professional on my HP CQ35. I made my first bootable device as cd rom and the second as HDD. The system boots from the cd and shows that setup is loading the files. And immediately after that a blue screen pops up and says a message. I’m not able to move further. the message states something like this setup could not continue if this is the first time………..chect for viruses on ur computer……run chkdsk-f….and so on….
So please help me out in solving out this issue.How can I install windows.Is it possible. I am waiting for ur reply…..
Thanks a lot in advance.
April 19th, 2010 at 8:02 am
Elroy,
You cannot replace the circuit board, it’s permanently attached to the LCD screen. If the screen goes bad the whole screen has to be replaced.
Nope, it’s not the inverter failure. You still can see the image on the screen, so the inverter/backlight lamp work properly.
April 19th, 2010 at 6:33 am
Hi Repair Man,
Just an update from my last post. I downloaded the “Powerstrip” utility and it seems to be able to compensate for about 90% of my screen’s problems.
I inverted the gamma, and most of the colours now display correctly but it seems with altered saturation, and a hint of “blurriness”. The “blurriness” does not manifest itsself as poor contrast or washed out colour, or poor brightness, but rather perhaps where there is shading, it is slightly the wrong colour so the display appears a little “off”.
Also, there are faint horizontal bars (about six to eight) scrolling up the screen at lower brightness levels. The “bars” look like the bars when an a CRT screen is videoed. The bars fade out to almost imperceptible when the brightness is set to max, but then the colours are bit off. Soon as the brightness is turned down a bit, the colours look better, but the bars return a bit, but this seems to be the best “comprimise setting” to make the screen usuable.
So my question: Do I need to replace the screen itself? Or the circuit board taped to the back of the screen (or is this board part of the screen)? Or is it the inverter board (which I’m not sure is damaged because the weight did not get exerted on the “hinge” part of the computer. I can also post some pics if it helps.
Thanks in advance.