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.
Need spare parts for your laptop?
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June 5th, 2009 at 1:05 pm
Well the new display inverter fixed it all,works fine all the way!
Robert
June 4th, 2009 at 7:25 pm
I am having a similer problem with my Gateway ma2 6021gz, When I power on the system the onboard lcd lights up gray and has no picture what so ever, an external monitor works fine, is this an inverter, lcd, MB, or video cable broblem??
Thanks in advance, Chris
June 4th, 2009 at 7:07 am
Sorry I got cut off (hit enter instead of backspace) while editing, its a HP DV6810US and running Ubuntu 9.04 linux ,,and I have checked all Power settings HELP! I do have a new inverter coming in soon, what does it sound like to you? I keep thinking weak inverter or weak power supply, I looked at the inverter and it looks like the clear plastic over the copper coil is dis-colored brownish like maybe from heat, are these normally dis-colored or remain clear with normal use? thanks Robert
June 4th, 2009 at 6:43 am
My lcd screen goes black on AC but works fine on battery, external monitor works ok either way, screen shows desktop when black on battery when shine light on it. Inverter,power supply or what is it??
Robert
June 3rd, 2009 at 2:12 pm
Hi, I have an issue with my Dell e6400. I dropped it, the screen broke with only half of it still displaying properly. I bought a new one from LCDWORLD on ebay and it works great, IF I’m plugged into AC. Trying to start up the laptop on battery will result in a blank screen while starting up on AC works fine. After the laptop is started up, I can disconnect the AC power and the screen will stay on. Any clues? Could it be the inverter? Why does the screen stay on even after unplugging from the wall?
Thanks, Franco
June 2nd, 2009 at 6:51 pm
Hello.
I believe my dv9000 is experiencing the issues described above; the only issue that has me wondering whether or it is the board itself is that when I plug an external display, I’m only able to view a broken image by booting into Safe Mode. The image has broken lines and a bit distorted. Any guidance on what may be the root cause? In advance, I appreciate your help.
May 26th, 2009 at 8:49 pm
Mark,
That could be:
1. Loose connection between the video cable and LCD screen or inverter board. Try reconnecting the cable first.
2. Bad video cable.
I don’t think that your problem is related to the inverter because you can fix it by moving the display.
May 20th, 2009 at 5:59 am
Hi, my Toshiba Satellite M105-S3041 has developed an issue where the screen dims when the screen is moved up and down or due to some vibration, there is also a buzzing noise when this happens. I have to move the screen around normally to correct it. Does this sound like I need to replace the screen inverter? or could it be the video cable that is faulty? or something else? It’s normally fine when there is no physical movement. Please also recommend a site to order the part from. Thanks!
May 18th, 2009 at 8:04 am
Shelley,
You’ll find the display disassembly instructions in the service manual, here’s the link.
You don’t have to separate the display panel from the computer base. You can remove the bezel while the display is still attached to the base.
May 17th, 2009 at 10:08 am
Please send “taking apart the display panel” for my Dell Inspiron 1200 laptop. I am going to try to replace the inverter. Hopefully, this will correct the problem. After reading all the comments posted here, I believe this is my problem!
May 13th, 2009 at 1:36 pm
Stan,
Could be connection related issue. Make sure the video cable is properly connected to LCD, motherboard, inverter board. Try reconnecting the cable.
May 13th, 2009 at 1:26 pm
I took apart and old laptop, put it back and the screen is now dim all the time. Besides that everything is fine. Could it be the inverter? Works fine with an external VGA connected monitor.
It’s a Dell Latitude C family.
May 8th, 2009 at 9:05 am
tom,
I found that Dell website is a very valuable source for all DIY-ers. They have very good laptop disassembly instructions and I use it all the time. I wish all laptop manufacturers would be the same.
May 8th, 2009 at 8:40 am
thank you!
it was the inverter. i never repaired any laptop but replacing the inverter was easy. i found instruction for my dell inspiron in the service manual from dell website. found new inverter on ebay for $25 and replaced myself. saved me $100.
May 7th, 2009 at 8:34 am
Repair Man,
Thanks for the info! I took the information about suspecting an inverter or backlight to the computer shop that built my first computer… I’m taking it in tomorrow after I dump my files tonight (just in case it’s the motherboard and I decide to not fix it).
Thanks for the insight though. I was definitely flipping out this morning and didn’t realize quite how common this sort of problem is with laptops.
May 7th, 2009 at 8:25 am
Elissa,
It’s either a bad inverter board (which is most likely) or faulty backlight lamp (which is less likely). If you have no test equipment and have to guess, i would definitely try replacing the inverter board first.
Here are instructions for taking apart the display panel in a Dell Inspiron 6400/E1505 laptop.
You don’t have to remove the whole display panel, it may stay attached to the laptop. Go straight to the Removing the Display Bezel instructions.
As you see, the inverter board is attached to the bottom of the LCD screen. You’ll have to figure out how to remove the inverter and replace it with a new one.
Replacing the inverter board shouldn’t mess any data on the hard drive but if you don’t feel comfortable doing that, take the laptop to a repair shop.
By the way, you can remove the hard drive from the laptop and install it into an external USB enclosure ($20-30 in a local computer store). After that you connect this enclosure to another working computer and access your data.
May 7th, 2009 at 6:22 am
I have a Dell Inspiron e1505… has worked fine with NO faults until this morning. I get up and the screen is pitch black. I restart the computer and I will get about 10-15 seconds of full color then straight to black. Several hours later I notice that I’m getting a “shadow” of my screen showing in the background when I was thinking it was black.
From reading a handful of pages this sounds like an inverter – am I correct in thinking so? I am able to get little flickers of full color (1-2 seconds tops) if I close the lid then re-open the lid.
I’d love to be able to do the repair myself and save a few $$s but I’ve never worked on my laptop and I have all the files for my company on it. Unfortunately I haven’t backed it up in a few weeks either. I can tell everything is there, but I’m worried that if I tried to do the repair myself I’d mess it up. Is this the sort of repair that I can entrust to Geek Squad? Also, would I be better off ordering an inverter myself or just buying it through them?
May 4th, 2009 at 8:24 pm
Linda,
Your description sounds like a problem with the backlight lamp inside the LCD screen.
From my experience, the red tint on startup can be cause by a faulty backlight lamp. Inverters do not fail this way.
May 4th, 2009 at 5:43 pm
Thanks! It was the lcd screen. Apparently the replacement screen was also defective. Glad I stumbled upon this site. Great information.
May 3rd, 2009 at 11:10 am
nick singh,
First of all, make sure the video cable is properly connected to LCD screen, inverter board, motherboard. It’s possible that you accidentally pulled the cable while replacing the screen. Try reseating the cable.
Yes, it’s possible.
1. Check the connection.
2. Replace the inverter.