Instructables

How to Replace Your Laptop's Backlight

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Picture of  How to Replace Your Laptop's Backlight
Is your back light dim? Does it start up with a red tint? Does the back light eventually just give out OR do you hear a high pitch hum sound coming from your screen? Well, here's part two of the laptop disassembly and repair. We're now moving away from exploratory surgery and into healthy repair.

Warning

CCFL Tubes are small fluorescent bulbs. As such, they contain mercury. It is also likely that they are made with lead glass, which is very brittle and has a low melting point. Avoid shock and unnecessary stresses on the bulb including prolonged periods of high heat (soldering iron). Do not twist or bend your bulb and do not wrap wire around it.
 
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Step 1: Parts and Supplies

Picture of Parts and Supplies
You'll need everything you needed from part 1 to disassembly your machine. But you'll need the following too:

1. Replacement Bulb
2. High Temp Foil Tape (EMF Shielding)
3. Soldering Iron
4. Solder Wick
5. Wire Cutters

Step 2: Disassembly

Picture of Disassembly
If you haven't done so already -- take your screen apart!

Here's how to take apart the HP zv5000: http://www.instructables.com/id/E8M1EZJF3YWV61Q/?ALLSTEPS

Step 3: Desolder Old Bulb

Picture of Desolder Old Bulb
Pull back the silicone end covers to expose the old CCFL's solder joints. Desolder using solder wick and remove the wire. My wire happened to have a nice through hole end.

Step 4: Solder New Bulb

Picture of Solder New Bulb
If your old bulb had plastic rings on it, like mine, be sure to transfer those over to the new bulb. Then, solder on the bulb's wires. Do not apply heat for more than 4 seconds. Additionally, place the wire at the base of the connection. These bulbs are not directional - so there is no "+" and "-" side ;)

Step 5: Trim Bulb

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My bulb came with long leads - trim these with wire cutters. Then, replace the silicone end caps.

Step 6: Place Bulb into reflector assembly

Place the new bulb into the reflector assembly just as the old bulb was (in my case, wires pointing "up").
Wolfrick7 years ago
You make a good point about the "mystery screws". A good use for a digital camera is to take progressive photos as you disassemble, with a macro setting or lens if you have it. Then, should a question arise, you can refer to the photos for help. I like using a bowl for keeping my screws as I work. I'm looking for a small stainless steel bowl to use, and I plan to epoxy a large magnet to the bottom to make the screws stay put even if the bowl gets bumped. Thanks for posting this!
I think you'll prefer the already built stainless bowl, Wolfrick, from
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90566
for $5US. Just what the doctor ordered for errant screws during a fixit project!
Even better, use a muffin tin. There are 12 or so individual small bowls that are permanently attached. You can use them in order of disassembly and use the bits in the reverse order as you reassemble. A strip of masking tape along the one edge of each bowls makes a quick and simple labeling system. I learned this simple trick from an airplane mechanic I used to work with. As we took inspection panels and other parts off the planes, you just placed the screws and other fasteners in the bowls. Available at any Wal-Mart, Target or grocery store.
I use a egg box (carton?) for 24 eggs. I wrote the numbers from 1 to 24 in the bottom of the bowls. And sheet of paper in which I write the number of the bowl and What I out in it. Hm. Took a Picture of it, but can't seem to attach a picture with the mobile site.
Earlier I saw an instructable for a loose screws magnetic Altoids round can.
Wolfrick It's easy to make a quick sketch of the equipment your are disassembling too. It is a technical's usual practice to make sure things will go the right places again... I've learned it from a friend who's a CASIO technician, and show this to a Japanese teacher from CASIO JAPAN... The guy never thought it could work so well... Warmest Regards dudaott
h2ofarmer1 year ago
Good job on your instruct. Thank You. Now to pull apart my Toshiba. This should be fun.
Udon3 years ago
Heh! I like your Chinese soldering iron. Tai hao.
trebuchet03 (author)  Udon3 years ago
Ni Hao!

That's the instructables iron ;) It's a Hakko something or other - I think it's a Japanese company/brand but very well may be manufactured in china :p

Your profile says mechatronics student.... what school? Any sweet robots?
billotto6 years ago
I did this one on a Dell 5150 with a 15" UXGA screen. It can be very very tricky to get that reflector back into place because you've got the lamp in there and don't want to break it. Meanwhile, you need to slip it around the thick (quarter inch) glass behind the LCD so that the light shoots up through the glass. The lamp has high voltage so you want to make sure there are no exposed wires. Those silicone rubber end caps might be torn after you get the thing apart. Bottom line, it can be challenging and you need good eyes and careful fingers to get it all back together just right. I felt lucky to have been successful. I got my LCD out and on the back it said "DO NOT TOUCH WHITE TAPE --- SENSITIVE AREA." Unfortunately, I had touched that tape when I flipped the LCD over to the back. Fortunately, it does not seem to have been damaged. Look up CCFL (cold cathode fluorescent lamp) to find a supplier. You should not need to spend more than $15 + $7 shipping. But I would strongly recommend ordering new end caps and wire to make the job easier and safer. You'll still save at least $100 in labor.
Good tip.  The LCD doesn't seem to be damaged because if you took off the white tape, there is a thin ribbon cable there.  This cable contains millions of tiny wires (3 per pixel) and at one point, right before it goes into the LCD, becomes so packed the wires seem to come together into a rectangle (they're indistinguishable).  They don't want these to break or short.  However, if you're careful, I found this cable can survive quite a bit of bang. =P (I took apart one of those LCDs completely).
By the way, it's a diffusion panel, made of mostly plastic, not glass. xD
Ryan
so thats what makes the screen all bright. but wouldnt a bulb make the lighting uneven (im not questioning ur method im Q'n the designers of lap top)
Fluorescent tubes are used for a few reason.... Here's 3: 1. Cost 2. Energy Requirements 3. Uniform Output So, by having low energy requirements, you save on battery power and can use a smaller pack - which saves on cost in that area. The bulb itself is cheap, but the inverter is a little more expensive. Fluorescent tubes have a pretty uniform light output - so I'm not sure why you'd think it is uneven. Perhaps you're thinking it to be more like an incandescent?
How do they dim the bulb? cause with a standard florescent bulb you cant just lower the voltage right?
the bulb never dims....the LCD matrix does all the work.
Opps didnt read #8 so the glass diffuses the light evenly i thought they just like had a a bulb going across the screen and that would make it uneven (i have 6 hour jet lag at the moment so im not thinking strait JSYK)
gassyandy5 years ago
I also have a Dell 17" Monitor built by the Benq for Dell The inverters in these monitors are always failing because of a design flaw, or rather cheap out. There are 4 transistors that are really hard to get that fail because they are not on a heatsink and wear quickly. Anyhow I decided that it was not worth fixing the inverter and instead found a couple of old point of sale touch screen machines. (486 mi-cos yuk) they had a really nice modular inverter that sported just 5 pins kinda like a square chuck of black epoxy with pins sticking out. these things are great it is too bad they don't use them today anymore but then again they are manufactured in Canada so go figure. if you happen across any of these old point of sale machines it is worth digging out the inverter module because you never know when you are gonna need 1500 volts... Now the monitor is brighter then ever and it did not cost me anything to fix it.
12V gassyandy4 years ago
i replaced one with different transistors it worked and won't go again (better transistors)
ReCreate5 years ago
i Got Myself an Old laptop With a Broken Screen, I Opened the Screen And Took Out the Backlight And the Inverter, Coincidentally I had another Old laptop,That Was A Similar Model,It had the Same Inverter And Cable,So I Tested the CCFL tube from the laptop with the broken screen and it worked,The Inverter+CCFL Worked Like a charm,Now I am Making Myself a lamp,I got that thing to run off of a 9V Battery,And a 13V Power source.
fegundez16 years ago
Before buying your replacement light,measure it!I found there are big differences in what they say the size is and what it really is.Example inspiron 1200 is said to have a 15 inch when its really 11.5!The light sellers even have it on their sites as 15 so double check!
How they get 15 inches is they measure from one corner to the opposite corner such as top-left to the bottom-right corners.
I was referring to the actual bulb,the screen may be 15,17 etc but if you order a bulb that is 15 for your 15 screen you may get a surprise! So make sure to double check.
now I get what you are talking about
billb5 years ago
This is a great and helpful instructable. I use a laptop (15" display) in my car 6 to 8 hours a day, plugged into a 110v inverter. The problem is on a sunny day the monitor is almost impossible to see any detail. I have an unused 15" desktop display. Do you know if I could put the backlight etc. from the desktop display into the laptops lid? I'm sure it would run hotter. Maybe a small computer fan could keep things cool. Should I attempt it or don't ruin both items? Thanks in advance for your advice.
timnrose5 years ago
I tried this on my sister's HP ZE2015US model. I started with a new CCFL, but it didn't come on after install. So, I found an eBay seller who had a replacement inverter real cheap, and when I got it, I swapped out the old one. I plugged in the power supply, and powered up. The ccfl came on for about 1 second, then went out. I booted all the way into XP, then put the machine into Standby. When I brought it out of Standby, the ccfl came on for a second, then went out again. I don't hear any noise from the inverter, so I don't know what the problem may be. Anyone have any ideas?
Detman1016 years ago
I wonder if there is a way to replace the CCFL with an LED strip... Dm
trebuchet03 (author)  Detman1016 years ago
Do it :) Then post the instructable
rpertusio6 years ago
Very useful when I had to replace the backlight of my ZV5000
Thanks for posting this! After replacing the inverter, I tried the backlight and using your instructions, it worked! My first real soldering project too.... I don't think my backlight is quite perfectly aligned as I can see some light sneaking through the bottom. oh well... I do have one question. If I press firmly on the bottom of the LCD where the backlight sits, I can hear a buzzing sound. Is that a serious problem? thanks, again!
This step-by-step laptop LCD disassembly guide will be useful for all DIY-ers.
Is it easy to replace the backlight lamp yourself? No!
Is it possible? Yes! But you have to be very very careful.
knufunk7 years ago
I just tried to replace my pavilion zv 6000's broken backlight (I dropped the laptop and the bulb went dead). after reassembling the screen enough to be able to see if it works, I found that although the lightbulb works, the screen is dim. I can see what's on the screen - it's kind of 50% of the normal brightness- but still dim, and on the bottom, where the bulb is located, the screen is brighter but unevenly, just at the lower end of the screen. Any idea what went wrong? can it be my soldering? or could it be that also the inverter got damaged when I dropped the computer? any help will be very much appreciated, I need my laptop desperately and know from previous experience that sending it to HP service will render me laptopless for weeks.
trebuchet03 (author)  knufunk7 years ago
Hrmm.... If you haven't already, check the solder connections - also make sure that the connectors to the inverter are snug. Is the bulb in it's reflector assembly properly? Is the reflector assembly on the glass panel properly (snug and such)? These are the easy to screw up scenarios - several of which I encountered :p Is the bulb lit evenly? Or, is it brighter at the two ends and darker in the center? If the latter is the case, the inverter is not supplying enough voltage (but I can't say for sure if replacement will fix that). At least, that is what I recently discovered on another recent project.
Punkguyta7 years ago
This should be handy for anyone who needs this replaced, I went to take apart an old toshiba laptop I have to use the screen in a projection unit, but I realised that it wasn't worth is seeing as the motion blur from it's age will technically make it of no use, problem is I went to put it back together and stepped on the tube which kind of sucks ratherly, warning to others: Be F****** carefully, these things are so fragile that you could probably break it by blowing on it.