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.
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February 24th, 2010 at 1:18 pm
Yes the Adapter was plugged in – I was using the laptop, and yes my husband checked the adapter. I cannot start the machine at all; with or without the battery removed and just the adapter. When I removed the battery the first time it powered up and the screen showed briefly, but then it went dead again. I did see the power and battery lights come on once or twice but now these also don’t light up any more. The person who changed the Inverter for me experienced the same thing at the time that I was. Unfortunately he is unexperienced and perhaps did nor insert the converter correctly.
February 24th, 2010 at 10:51 am
Elizabeth Barnard,
Was the AC adapter plugged when the lightning struck?
Maybe the lightning damaged the AC adapter. After that the laptop worked until the battery got discharged. Now you cannot turn it on because the battery has no charge and AC adapter is dead. I would test the AC adapter first.
If the lightning struck when the AC adapter was unplugged and now the laptop is dead, probably it damaged the motherboard.
Can you start the laptop just from AC adapter when the battery is removed? Can you see any LED lights on the front when AC adapter is plugged in?
February 24th, 2010 at 4:24 am
I have an Acer Aspire 5610Z Laptop which has been damaged by lightning. Up to now I have not been able to find someone who can definitely say what is damaged. When the lightning struck there was a flash from where the adapter connects to the laptop and the machine went off only to immediatly power on again, it then continued working fine for a while. When I returned to the laptop later it had switched off and would not restart. I have tried various recommendations, for instance remove the battery for 30 sec., connect to an external monitor and lastly to replace the Inverter. None of these efforts produced positive results. There is no sound or anything remotely visible on my laptop now.
Could or would you be able to give me some idea as to what may have been damaged and if it would be worth repairing.
Thank you for your advice.
February 23rd, 2010 at 2:13 pm
Jman,
Can you see the BIOS screen on the external monitor.
What do you see on the desktop the other 50%?
Can you see a very faint image or it’s completely blank?
Have you checked connections between the video cable and LCD screen/inverter board.
February 23rd, 2010 at 4:08 am
I got a odd problem, got a dell vostro 1710 and the screen got sat on. Got the replacement screen and had issues with the frame so had to swap with old frame to get holes to line up. now when it boots I do not see the bios screen but the black screen lights up some. but when I get in windows and see my desktop 50% of the time I see it OK, I do have it hooked to an external monitor so I know the computer is AOK. do you think my inverter is bad or the new screen? Have you had to replace the frame of a lcd, maybe I got something messed up there? any help would be great.
February 22nd, 2010 at 10:42 pm
You are an absolute champion, This had been driving me crazy since i had my brand new laptop 3 months…. i put up with it for 2 years.
Then finally it stopped backlighting at all like you said.
I was about to remove the screen completely to use it as a 65w server, and just terminal in… lmao.
Russ.
February 20th, 2010 at 2:40 pm
Ivana,
It’s necessary to disassemble the laptop and take a closer look at the internal parts. I guess you’ll have to take your laptop to professionals.
February 19th, 2010 at 8:38 pm
Hi,
I spilled water on my laptop hp compaq nx7400. Now when i try to turn my laptop on it starts normally and then screen goes blue.
Please help me. After I spilled water I dryed it with blow drier.
I don’t know much about laptops.
February 18th, 2010 at 7:18 am
Tq on your advise…
February 12th, 2010 at 1:44 pm
senaville,
Nope, it’s not related to the inverter board, that’s for sure.
That means the video card is working properly.
I think it’s either failing LCD screen (more likely) or problem with the video cable (less likely).
I would try replacing the LCD screen first.
February 11th, 2010 at 7:42 am
Hi, (continue) in my case with my lenovo Y410. I already tested to hooked it up to an external LCD and the screen on the external monitor is just fine. Just for your info. Any help is appreciated.
Thanks
February 11th, 2010 at 7:33 am
Hi, i have lenovo y410, the problem is with the lcd display, after it on then the dispaly start to vibrate vertically. Sometimes, the image which should at the top but it can be view at bottom of lcd display.
I’m not sure the lcd or inverter failure… Anyway how to test the inverter?
Thanks bro
February 10th, 2010 at 11:01 pm
Jorge,
Can you see the entire desktop image on the working part of the screen and it looks kinda compressed, or the black stripe on the right side covers part of the desktop image and makes is unusable?
February 6th, 2010 at 1:31 am
I have an acer 5610 about one fifth of the lcd on the right is black but on an external monitor it shows it all what could be wrong?
January 27th, 2010 at 3:11 pm
robija,
It’s possible that you have a faulty backlight lamp inside the LCD screen.
You can test it with a known good backlight lamp: http://www.laptoprepair101.com/laptop/2009/05/04/how-test-lcd-screen-inverter-in-laptop/
January 22nd, 2010 at 5:53 pm
when i start my toshiba satelite a135 nothing is lightin up but i see picture in the back , bought it a new inverter still nothing picture still in the backgroung… any sugestins.. thnx
January 20th, 2010 at 8:53 am
Hi Repairman, today I had removed the RAM but the problem wasn’t rectified, so I took out the Inverter and replace it with another one from a different model Toshiba laptop and the screen lights up just perfect but I didn’t leave it hooked up long enough to observe the cd drive cause of the fear of ruining that one. I also did the procedure vice versa and it was indeed a bad inverter cause the known good laptop screen stayed blank. my inverter has 7 pins and the other one has 6 hence the reason that I had removed it quickly.
January 20th, 2010 at 12:03 am
bill,
You’ll have to test your laptop with an external monitor. If the same problem appear on both internal and external screen, your problem is related to the video card failure.
If red tint appears only on the laptop screen and external video works perfectly, most likely this is the backlight lamp failure. The lamp is mounted inside the LCD screen and very hard to replace. It means you’ll have to replace the entire LCD screen.
January 19th, 2010 at 11:59 pm
Michele,
Find the inverter part number and google it or search on eBay. Buy from a reputable place.
The part number will help you a lot.
You can find the part number in the maintenance and service guide (can be downloaded from HP website).
January 19th, 2010 at 11:39 pm
vinz,
Did you test the laptop with an external monitor? Can you see the external video?