Thank you for posting this video. Shining a flashlight at the screen was extremely helpful in trying to determine what was going on and was something I would never have thought to try on my own. Thanks again!

Well great, I'm gonna do this with my monitor, I just need to pull a little testing device thingy out of my ass...

Cheers Miguel, its one of the most common issues on a laptop and people are always stumped on what it is.

Hi Pat, Hope you get this. Issue is *definitely* your inverter. Being a month ago you probably have already installed the new one and it should be all good.

Awesome thought using a mini ccfl power supply like that. It never even occurred to me! I can pick one up for a few bucks. I have the same issue. Though am just working out if it is the inverter or if its a control circuit in the laptop itself. Im going to go with the inverter as they are cheap. Worst case you rig something up and you dont use brightness controls. Theres always ways around these things! Good video!

You can make your own or you can buy them on Ebay, come in very handy and its fast diagnosis.

The issue can be also related to a faulty GPU, sometimes when the GPUnit desolders itself you can get weird combinations of the video output like nothing on the internal display and a normal output on external vga or hdmi, it can be like half picture or only graphical content without backlight, distorted video output, lines, low brightness... first thing when I have a laptop in my hands with a faulty GPU I "reflow" it and if then still doesnt work as it should than Ive must re-ball it :P

Hi Britec09 At 3mins 19seconds - if you get a display using the CCFL tester, how do you then know the inverter is bad and not that the inverter doesn't get an enable signal from the laptop motherboard? Doesn't that also need to be tested?

The inverter on one of my laptops failed and I didn't want to spend any money on a new one, so I searched for ways to actually repair the thing. Unrelated results came up so I inspected the miniscule board and came across a tiny fuse which looked like a rather large cloudy LED. I bypassed the fuse with solder (after testing with a pair of metal tweezers) and my backlight works once again! Word of advice, CHECK FOR ANY FUSES BEFORE ORDERING A NEW ONE ONLINE! You could save some money :)

Thanks for this very helpful video. May we know what kit you use to diagnosed the inverter?

This happend to my Dell more times than I could count but I was never quite confident enough to fix it. Might just do it now :) Thanks Brian

I don't have tools to test it, but I opened my LCD and took out the back light and plugged it directly with the inverter. The backlight turned on however it turns of in case I move the backlight cable a little. The backlight turn on when I refresh the screen from a function button on my Toshiba laptop. It seems that its not the backlight but the inverter which is bad because the backlight wont turn on at all if it bad - right ?. are you able to suggest if its inverter or backlight ?

HI! Thanks a lot for this video. I really would like to know where can I get the backlight and inverter tester?

You can make your own or buy one on Ebay.

Thank you very much. A good demo. It would help even more if you told viewers where to get the inverter tester from. eBay ?

where do you get the kit you show in the 2nd part

Hi Dave, Its cheap and quick and easy to use, saves a lot of time also.

Yeah have seen that its a nice tool Gary, have a great week end.

I had the same problem once with my Nvidia 560ti it was down to my drives I had to roll back to a older more stable drive.

Good job. Helpful video. But how to find old inverters or bulbs to buy?

Hi Rob, sorry for delay try and search for inverter tester

Where can I buy this KIT you're using in this video?

Hello there. My problem is that of, when I turn my laptop on, I see images like the backlight is gone. I plug it into a monitor and it shows up bright for a second and then goes to the no backlight feel again. Hopefully it's the inverter but I just don't understand why the external monitor is doing it as well. If you can get back to me that is great but most likely by the time you do I'll have it fixed or fed up.

i need help, x220 back light not working, i tested the led pins on the actual panel, and they have no voltage. i dont know if the led driver is on the motherboard or the little pcb on attached to the panel.

Yeah they will be coming soon when I get back in my workshop.

There is better kits for testing LCD and LED screens and there is also converters that convert LCD to LED :)

Hey i detached the screen from the main laptop and i just need it to light up for an proyect. How do i just turn on the screen backlight i wasnt to clear.

i have a question to this. what if the LCD monitor keeps randomly turns black screen and comes back on? does that means it has faulty PCB?

ive been trying to figure out my dell screen for months. At first the screen was getting lines in it and so I replaced the cable. That fixed that problem but then about 8 months later the screen turned bright gray. It's not any display settings or video card as an external monitor works perfect. I put a light up to it but can't see anything and the screen is bright anyway. Turns instantly gray as soon as you turn on the computer. Pressing "D" on bootup to toggle the screen diagnostics displays various colors but after its done goes back to gray. After using the computer for a few days on external, all of a sudden the screen worked perfect again for about a week until I once again received the gray screen. I tried replacing the cable again but that didnt help. So I am down to either the inverter or lcd monitor. Any ideas?

Nice video! I have a Sony VGN AR630E, not sure what model you used for this video, but it looks similar to mine. With a strong light behind me, I can see the Windows desktop. Not sure if it's the bulb or inverter. I would really like to get this laptop running again. Amazon has several inverter test kits. Are they all generic enough to work with any display? I have no test equipment. Based on what I saw in your video, I would need a test kit, a power supply and a thin tool to pry open the case. Can you tell me what power supply to use and where to buy that tool? Thanks!

Aha! Just my problem with my old Dell D600. May I suggest a future video for those of us on a budget, who have a couple of old laptops hanging around. Say two Dell D600s, one more powerful than the other, both with hardware problems. It would be fun to know how to dismantle two old Dells and build one good one out of the parts. Could we combine Mhz, RAM, Ghz, etc.? And how do we move the good screen and the good keyboard over, and pop in a CD-DVD drive, things like that. Thanks for your time.

Could you possibly do a disassemble video of this laptop?

Which begs the questions.....How and can one replace the inverter? Where does one buy an inverter if they can be replaced? Is the inverter built on to a replacement screen? Are the backlight tubes built on the screen and how to replace them?....

Hi, Just recently (a few days ago) my Dell Vostro A860 started acting weird... after shutting down unexpectedly & turning it on after a while, a small black smudge appeared in the place where the time is displayed on the LCD (bottom right angle). I immediately thought this was a failing CCFL bulb, but I didn't replace it. Today it destroyed my inverter (blown fuse actually). Thank God I've got a spare CCFL bulb for this type of screen. Can I still salvage the inverter or not ? Some suggest just making a solder bridge where the fuse was before, my father suggested that I use a resistor instead... Thanks.

i got a screen where the back light turns off but comes back on again when taking the screen cable in and out of the mobo but as soon as i move the screen or touch the black cable it turns off the light again. the screen stays on throughout just no light. the first issue i had was flashing white lines which fixed by tapping the side so bought a new cable and now the issue above...

Where did you purchase the kit that you where demonstrating in the video , does look like a very interesting but of tech to use to diagnose problems with laptop screens.

My screen works fine, I can see it with a very bright light. Can I use this to test my laptop back light? ---> I have a portable "inverter". It is actually a device that powers a small tube-light to make your clear plastic PC cabinet look cool. It is powered by plugging it into a normal PC power supply component-connector. That tube plugs into the device (like yours), but I don't have any adapters that match a Toshiba inverter, I have a 50/50 chance (two wires I believe) for it to work by jumping it, but then again, is it safe to do that. It can't be more than 12 volts.

Cheers mate, yeah there is always a risk when repairing any electrical component, not a job for a non tech guy really.

cant find the inverter on my hp dv4 5113cl, replaced the screen but still no lights no logo. Help

Hello I have pc specialist recoil lll that's faulty the issue I'm facing is when I start the laptop the screen starts blinking on and off it boots into the bios just fine and I can't see any lines or artifacts I took the screen apart and measured the VLEDIN and the voltage wasn't stable going between 17~19 vdc so I then thought let's put a stable 19v and see what happens and the back light got brighter and my power supply started to click matching the screen blinking my thoughts where maybe its something to do with the power supply chip on the screen or the super I/O chip but as a complete beginner I've reached a dead end any help would be greatly appreciated 🙏

Yeah bit of a nightmare sony, they have always made it tuff to take apart.

I have a hp 2000-369wm with the same symptoms like the sony but it has a led backlight with flat ribbon that hooks on the bottom part so I checked the light with different screen and it lights on but not on the hp my problem is I don't know where is the inverter or this screen wont use inverter I let me know thanks

Great vid Bri, That should point some people in the right direction.

Nice vid, but where can one buy such a kit to test the screen?

If the LCD flickers when moving it and it does not occur with an external monitor could it be the LCD itself or the Inverter/Lamp? It glitches to with red and green artifacts when you move it. I took off the Bezel and when I touch the Cable it flickers but how does that prove its the cable alone and not the GPU or backlight/Inverter/LCD?

So if the screen is very dark and you can see the screen slightly is is the backlight or inverter

Yeah its on Ebay, I hook you up in TS

Please can you tell me what's the output voltage of your lamp kit ? And is it ac or dc ? Please let me know

Not bad, the little backlight tester is handy

Hello Brian, Great topic. And like others here, looking to pick one up for myself, what is the title to search for on EBay?

Great Video Brian and a useful piece of kit.

Many laptops have the inverter board built into the panel....

So....If you plug in the inverter tester (BECAUSE it's bypassing the old inverter), and there is NO DISPLAY, then the backlight lamp is bad. Replace the backlight. But if you plug in the inverter tester and you HAVE A DISPLAY, then the inverter is bad (because the lamp DOES work with the bypass inverter. Replace the inverter. If you gradually see the sccreen fading, it's LIKIELY the backlight is shot. If the screen suddenly went off it's likely the inverter is shot. Is that a correct diagnosis? i assume: Test the inverter FIRST because the lamp replacement is tricky.

Hi, Ive a Macbook and the screen is Dim I can see but its very dark when I boot into OS I can bright it up to normal but then about 4 sec and the screen goes dark so no way to see then.So If i dont change the brightness it has a barely seen display but If i change it goes total black, IS it the INverter? or the display it self?

I don't have the fancy tester so I would like to tell you my symptoms. I have a DELL E1505 and when it boots up I see the screen and everything looks normal for a split second then I hear a electronic zzzz sound and screen goes black but like in your video I can faintly see everything on desk top. when a outside monitor is connected I see it all normal. I ordered a inverter on ebay......do you feel that is my solution given these symptoms????

Can we get a link on the videos description on were to get the tools?

Great video Brian, here is a to a tool that I have used for a long time that you might like to try called the LST01 V2 - Laptop Screen Tester. Regards Gary

wheres the link for the Laptop Backlight or Inverter Problem KIT ?

I bought a new Display, still the same problem (no backlight) #facepalm

I see what I can do.

NEED YOUR HELP have an acer 8930g, wont load a good working hard drive at first would turn off before loading up windows, now just sticks. could it be a bad capacitor? and could this affect the inverter, as i bought a new inverter it lasted 5 mins while i was investgigating the other problem, all other hardware works, tested graphics card etc..thanks for any help//

i dont have this device, ive bought several inverters now n they either dont work or quickly fail???help

I cannot rly use light to check as i have virtual reality headset and if i shy light lens will probably burn into headset :/

Thank you for making this video!

Your welcome.

thank you for help

I checked ebay for that tester and couldn't find it. I really have researched this so much I could have had a PHD by now.....lol

hey, just wondering if you could do a video on how to move your os from a hdd to a ssd thanks!

First of all thanks for this tutorial. I live in Indonesia, we don't have specialised shops with those parts. I don't know if it is indeed a problem with the Backlight itself. I installed a new lcd inverter but unfortunately the problem wasn't solved, it's the same. It is intermitent: Sometimes I start the computer (HP Pavilion dv2000) and the screen is illuminated, but more often it isn't, altough I can see there is image. After some tries (putting it to sleep mode and then on again) it sometimes works (I am writing on it right now, but I am afraid of ruining altogether). Do you think it is the screen, the backlight? There is always image, only mostly with no light. Thanks!

Your welcome mate.

Tried this, the backlight lights but not entirely. theres a dark patch.... bummer

very helpful. thank you

I think that I have problems with the inverter because sometimes I have a dark screen and sometimes I have a normal screen.

i tried the IBM ThinkPad 380ED use a Flashlight aiming it to the screen i just See a Display

How do you perform the test with the multimeter

My brother has the same laptop, having a hell of a time getting it apart.

I have a dim screen issue (when lighted with a flashlight, I can see the screen) - I have a Toshiba L655-S5146 (Model No. PSK2CU-0Q001T). This is an LED screen - does not have an inverter (CCFL). Through an external monitor, I can see the display. I have already replaced the entire LED screen, but it does the same thing - dim screen. Any other options out there? I've heard that some laptops have some sort of pin that is stuck and letting the computer know that the lid is still closed - but I don't know where to search for this, since there are no latches on this model.

Hi Brian. I usually see your videos, ty for them and for explanations I have one question and i hope u can help me out. When im seeing a video on You tube, a movie or a website with videos, my computer just shuts down. It freezes and shuts down. All screen turn blue saying "recovering data.." some % to 100 and reboots itself. Can you please tell me if its a virus?

My problem is that the screen light only goes off when the charger is plugged but works well on battery

Hey do you still have the computer you used in this tutorial?

On Ebay mate.

Thanks brian :-) An En-light-ning tutorial lol, sorry i just had to say that :-> led's are the thing for new display backlighting but its going to take quite a few years for the population to replace there loved lappys. Have you found any good led strip kits to replace the tube as ive noticed a change in the lvds connector in new screens, dropping a modern screen into an old lappy is not soooo easy ? I use an old acer aspire 5315 and was thinking about it.

Thank for your time, this helped me alot.

where can i get the kit?

......../.......................................... where is a link to the kit mentioned at 5:20 mark ? What is it's name or description ? Thankyou

Great little tool. Do I smell something burning?

Hello, thank you for helping people like this. Can you please diagnose what the problem is with the screen of my Aspire 5532? Sometimes, immediately when I turn ON the computer, the screen is dimmed to about only 10% of light just like when you use Fn+F6 to dim the screen, and I have to darken the room and then point a flashlight against the screen to see better what’s on the screen. When the boot pauses asking me for the BIOS password, I take the opportunity to try to disable the dimming by pressing Fn+F6; and 1-sometimes it works right away but 2-sometimes it takes a lot more tries and 3-sometimes when it finally seems to work what happens is after 1 second it dims again forcing me to try just a few more times. And there is more; each time Fn+F6 doesn’t work, I notice that for just 1 microsecond the screen was getting more brightness but it couldn’t complete the job. The next time it happens I will connect an external monitor to see if the external monitor is also dimmed or if it is OK, but maybe the information so far is enough for you to diagnose the problem??? Thank you again.

When we tried, couldn't do it and we ended up losing screws some how...

how do i repair it?

For Windows users. In case anyone's laptop screen has gone "dim", but is still functioning. First try going to start- control panel - systems and security -power options. Then (at the very bottom of the screen) move the slider to brighten the screen. That might be all you need.

how can i find the stuff for testing?

What about screens with LED backlight?

Actually it's a simple thing to figure out. If you can see windows running in the background when using a flashlight. Then it's the screen. If you can't see anything, then your inverter is bad. That's how I told my neighbor to do. I ordered a screen & put in his laptop & he's going again.

Thanks man, its a typo lol my bad, thanks for correcting it for me.

Another quick and dirty way to test the inverter is to use a non contact AC voltage detector. Just hold it against the front of the bezel where the inverter should be and it will light up if the inverter is ok.

what if the whole screen works fine but the right corner is dim like always at 0 brightness ( i can still see through it but its just dim)

I have the same problem and I won't fix it myself. Seems pretty east but I don't wanna ruin it (meter mano) How mucho would they charge me for that job? Alguien que viva en México y me diga en cuanto sale la reparación porfavor. Nice video

I have a odd and old laptop laying around. an Flybook V5 The backlight sometimes doesn't come on, other times screen works fine for X amount of minutes. First I suspected a loose connection somewhere. I ruled that out, it's not triggered by movement screen/wires/connectors Which leaves me with blacklight or inverter. Can a backlight develop such a issue? As far as I know they can't. That would mean the inverter is dying on me? (really hope not, I can't find a suitable replacement)

My acer is on its just dark what to do

how does this help me solve a problem?