A (very) Simple LCD Backlight Fix

 by bchafy
Featured
Fix any broken LCD backlight with an ordinary light bulb and a dead CRT monitor.

Broken LCD monitors basically come in three categories:
1) Cracked LCD panel, rendering the unit completely worthless
2) Backlight problem
3) Power supply problem

If it's a backlight or power supply problem, it can be fixed.
Usually, the problem stems from the high voltage inverter circuitry, either bad power transistors, capacitors, or thermal stress on the circuit board leading to broken solder joints.
But fixing these problems can often be a short term solution. The bulbs themselves have a limited lifespan, and the high voltage power supplies are prone to failure.
The panels themselves almost always outlive the backlights and high voltage power supplies.
The 17" Dell LCD monitor I found was no exception. When I first plugged it in, it would cycle power on and off continuously, with a notable burning smell. Further inspection revealed a fried power transistor. When i replaced it, the monitor stayed on, but the backlight would flicker on and off, then finally shut off after a few seconds..
The panel was good, but trying to fix the backlight with the proper parts wasn't really worth it.

But maybe I could still save it, or even make it better. After all, it's just a light. Lights should be user-replaceable things anyway.
I mean, a Lite-Brite was the cheapest toy, yet you could at least change the bulb.
So here's the result of my experiment, with help from an old CRT monitor:
 
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Step 1: Go to trash, locate a CRT monitor

Take a CRT monitor, remove the guts and dispose, keeping just the shell and monitor stand.

Install a light bulb socket about 1/2 way back. I used switching socket from an old lamp.
(for the bulb, I used a 60w-equivalent "daylight"/6500k CFL bulb. It has a blueish glow to it. )
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74LS374 says: Apr 14, 2013. 9:41 AM
I likes this idea... simple and cheap...
RetroPlayer says: Jan 8, 2011. 4:02 PM
I don't mean to be a spolisport, but... why? The whole point of an LCD monitor is that it is thin and saves on desk space. You just made it as big as a CRT monitor, out of a CRT monitor. Why not just use the CRT monitor instead?

::Blank Stare::
mr monoply33 in reply to RetroPlayerJun 5, 2011. 5:35 PM
One functioning screen is better than two dead ones. CCFL bulbs bought from a reputable place can cost upwards of $70. I'm going to try to wire an LED array to get a screen of mine working. If that doesn't work, I may do this. SO MUCH potential in a dead screen.
mr monoply33 in reply to mr monoply33Jun 9, 2011. 10:42 AM
Edit:
The new bulb will cost about $10, $70 was the LED substitute for the cold florescent, but I still wouldn't install one. I don't even like taking them out. I ended up buying a foot of white LEDs from a novelty lighting site for about $8 and it works great. Right now I'm powering the back-light separately with an un-used plug from my computer's power unit.
outbackshaq says: Jun 1, 2011. 7:28 AM
I wonder what would happen if you had a plexiglass panel and drilled holes on the edges. then in those holes you place superbright white leds, then on one side of the panel you put a tinfoil sheet. would that make an even light? because the leds arnt facing the screen. you could also sand down the frotn of the panel to make it less clear
gana_anaq2 says: Oct 7, 2010. 1:35 PM
Great idea ! For a better illumination try to use fluorescent bulbs ( the old ones like tubes) and in front of them put a laminating foil unheated. This is a mate surface and it will make the light to distribute uniformly. The led solution is not good because the led is omnidirectional, and you will see the spot where the led is.
For an estetic look try try to put 12mm fluorescent bulbs ( like in emergency light {EXIT} ) inside the original case, and the inverter for that lamps put it with wire in a separatly box :)
Timofte Andrei says: Sep 12, 2010. 1:57 AM
put a mirror inside the crt-case ;) oh...and use an AC variator for the bulb ;) if you wanna change the luminosity ;)
cyberraxx says: Jul 26, 2010. 10:44 AM
Nice one. I May be able to get hold of an LCD with dead back light. I wasn't too sure about how to go about reviving it. May try using supa-bright LEDS for back light and some sort of diffuser.
nessim says: Jun 4, 2010. 6:33 AM
very nice : )
motogen says: Apr 23, 2010. 3:04 AM
i only have the sme thing as same as the finish one aove,but when i turned on the power seems like nothings happened,i know there somethin i didnt door something wrong i did please advice thanks
motogen says: Apr 23, 2010. 3:00 AM
please tell me what to do im really having a hard time working on this and i  still cant get it right,ive been doin this for 3 dys now and still im ariving at the same situation
motogen says: Apr 23, 2010. 2:58 AM
im doing the sme project as you did right now,i have 3 thin paper like  pastics 2 are identical and one with a border,should i leave them and taking out only the fiter like  glass and a white one?when im done working on it i have no display,the power is  on and it has a indicator telling the monitor i turned on,is there anything you cn advise thanks
motogen says: Apr 23, 2010. 2:37 AM
i do the same thing as you did,i have a power my  screen goes white as same as the photos  on yours but i still dont have a display,everytime i turn it on,all i have is a white glowing screen,i havent connected the cpu yet,any second opinion if  there's something wrong on what i did,i have no display please reply thanks
animal0307 says: Apr 8, 2010. 3:06 PM
Use an LED light bulb. With cut down on the heat some, be more efficient and brighter.
hjartland says: Mar 11, 2010. 11:38 AM
Nice.

Announcing the lightest CRT ( ish ) monitor ever! :P

Have you thought of a strobe? ( NOT for epileptics )
Aloys says: Nov 4, 2009. 9:05 PM
Am I the only one who sees the steampunk potential here? A nice brass frame and a few candles or an oil lamp...   Wouldn't be very practical of course, but it would look amazing.
Stannum in reply to AloysFeb 27, 2010. 4:29 AM
 That is an incredibly awesome idea. But I don't know if in would be bright enough. Apart from that, I'm doing it as soon as I find a broken LCD!
magiccowy says: Feb 19, 2010. 5:06 PM
that looks brilliant. not only does it fix a monitor it gives it a retro-type look and a cool lighting effect. Would it be possible to put coloured perspex over the side vents to make it blue or something?
pimpinparrott says: Feb 17, 2010. 11:16 AM
nice instructable. but would it be easier to put an led array behind the screen so it would be thinner?
therockof2004 says: Feb 11, 2010. 9:10 PM
 Very Nice.

enderak says: Jan 19, 2010. 5:12 AM
new lcd screen is lightning spread :) use silicone  or same 
Arbitror says: Jan 8, 2010. 4:46 PM
Wow! Not only does it function fully, it looks cool too!
bill2009 says: Nov 8, 2009. 7:00 AM
that's great - thanks for the idea and how-to.
ac1D says: Nov 5, 2009. 2:18 AM
may I ask you what game is it?
cornboy3 in reply to ac1DNov 6, 2009. 1:06 PM
Lego Indiana Jones it looks like
ppatches24 says: Nov 4, 2009. 9:43 PM
dude so smart i live near a collage and there is a dump area for old computer stuff and there were two really good monitors but the back lights were broken and i do not want to pay for them i am doing this :))))

I am so happy i can use them now

Sweet job!!!!!!!!!!!!!!
Skor459 says: Nov 3, 2009. 11:55 PM
 That is so ghetto.
The ambient lighting in the last picture is pretty cool though, something people would probably pay extra for on a store-bought monitor.
Voodoo6666 says: May 20, 2009. 1:15 PM
cool Instructable! recycling... On the last picture ,is this a Dell d400 ? Sorry for my bad English I'm from Germany
tanmanknex in reply to Voodoo6666May 26, 2009. 7:48 PM
What bad english? ;D
srhadaham in reply to tanmanknexNov 3, 2009. 10:07 PM
I agree, compared to all of the "text talk" and slang people use today you seem to have a solid grasp of the language.
GorillazMiko says: Nov 3, 2009. 8:54 PM
Simple, and so effective!! :o
 
incorrigible packrat says: Sep 12, 2009. 8:45 PM
Sweet! I'm tempted to either make a Lite Brite out of an old crt monitor, or put an lcd panel in one of those funky old television cases.
tinnyjl says: Aug 17, 2009. 8:57 PM
THIS WILL BE A GREAT TO SAVE SOME MONEY
djupblue says: Aug 8, 2009. 4:10 AM
Just a tip, cover the inside of the crt-case with aluminim foil. That will give you much more light!
ReCreate says: May 31, 2009. 1:19 PM
What Happens When you remove the diffusing sheet,Do you End up With a See through screen?
mr monoply33 in reply to ReCreateJun 25, 2009. 1:24 PM
for the most part yes, in the two screens I've taken down, the screen its self is a deep purple, it doesn't turn clear-clear, still hard to see thou, but its good enough that is you get an over head projector, and lay that over it, it will project your monitor, and give you a jumbo screen, not great on resolution, but pretty good for watching tv & movies on youtube :)
ReCreate in reply to mr monoply33Jun 25, 2009. 1:39 PM
Ha...I tried it now, You do end up with a see through screen!
kiwimac says: Jun 25, 2009. 1:20 PM
Great idea and a simple way to fix a transistor problem.
donderlallo says: May 10, 2009. 8:32 PM
What about also using something like an aluminum / aluminum foil, white or otherwise reflective concave screen behind the light? Or even a shiny metal bowl, similar to what is used in headlights on cars or flashlights, to push most of the light forward and through the LCD? Thanks so much for this idea, I'll be putting it to good use :-)
Barry A says: Apr 23, 2009. 5:05 PM
Just toying with the idea of energy saving bulbs which give a more defused light and less heat , i will let you know
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