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DIY LCD Backlight Repair
Bill Nye (not the science guy) writes to tell us that InventGeek has an interesting article on do it yourself LCD backlight repair. From the overview: "Those of us that have used LCD monitors for a while know that over time the backlight starts to dim and will eventually completely fail. Leaving you with some electronic scrap that you could sell on eBay for 35 bucks or so. Well for less than $20.00 and about a half hour of your time you can replace the backlight and rejuvenate that monitor to as good as new condition."
Time to buy some cheap monitors on ebay!
"pr0n": An anagram of "porn," possibly indicating the use of pornography. - www.microsoft.com
Forgive me for asking...but would a similar process work on laptop screens? I've got an old laptop whose screen is completely fubar and this may be the problem...
I may be wrong but you're downright ugly!
Just FYI Fry's carries everything you need, from those special power modulators to mini flourescent tubes to repair your LCD's.
Now we deal with the case lighting. The cold cathode is incased in a plastic case to protect it and defuse the light. We will need to remove the casing very carefully. Most cold cathode tubes have mercury vapor in them this is very dangerous if it was broken. Avoided damaging the bulb at all costs as mercury vapor has been linked to brain damage and cancer. so be careful.... unless your some arch-villain with a diabolical plan.
Wait... complicated instructions that can lead to brain damage and cancer if done improperly, given to me by a guy who can't be bothered to fix your->you're mistakes? Somehow I don't think I'll be trying this fix any time soon.
A barely legible article that contains the absolute minimum information about a potentially lethal operation involving jillions of volts of capacitance and using power tools to cut almost-but-not-quite into one of the most toxic substances around, which, not at all incidentally, we are advised to just "dispose" of when we're done with it. Gee, I wonder what the author did with his? Tossed it in the garbage, or throw it into the sewer?
Frankly I'd rather that we just linked to bomb making instructions, as it would probably result in fewer acute injuries and chronic health problems.
If you were blocking sigs, you wouldn't have to read this.
Here's a little more info that laptop users might find useful and I stress "might". http://iantha.vectorstar.net/ccfl.html#replace
gasmonso http://religiousfreaks.com/It'd be a lot cooler if you replaced the bulb with a blacklight instead (press cmd-opt-ctrl-8 on a mac for a simulation)...
Be a real patriot: Question authority. Think for yourself. Formulate your own conclusions.
Under normal condidtions Mercury is a liquid. Still toxic, but not breatable. If the tube breaks open it will be exposed to regular atmospheric pressure and should return to liquid state.
Still, if you can get $35 for a piece of junk go for it.
"And we have seen and do testify that the Father sent the Son to be the Savior of the World"
1 John 4:14
LCD backlights are seldom bright enough when I want to sit outside (I know, I know, outside is sooo unnerdlike but sometimes it's nice to sit outside while working at a coffee-shop). But why try to compete with the ultimate light source? If the back of the laptop lid could swing open or be removed, then the sun could flood in. A diffuser/polarizer on the back of the LCD would let the sun be the perfect outdoor backlight.
Two wrongs don't make a right, but three lefts do.
Yes, I've been able to fix multiple different laptop screens this same way as well. IBM T21's T41's etc... Most laptop lcd are relativly easy to dismantale is you've got a sharp set of #000, #00, and #0 phillips screwdrivers. I found almost all my bulbs from http://lcdpart.com/. I found there prices to be really affordable as well, $10 for the 14"-14.5" bulb! You'd be surprised how easy this whole procedure is if you can solder a few wires. ;-)
and it is easy to do. I'd start with the inverter first and then if that doesn't do it, look at replacing the light. There was an ask slashdot about obtaining lcd parts a while back. You can read good info. in that thread.
I also wrote up a journal entry when I fixed my dad's laptop, but I can't find it. (Note to self, do better job with titles)
I was nervous the first time I replaced a laptop inverter - but it was cake. The best place I found to buy the hp inverter I needed was ebay.
It's hard to believe that's how Micronians are made. Why don't we see it right now by having you both kiss one another?
"The cold cathode is incased in a plastic case to protect it and defuse the light. We will need to remove the casing very carefully. Most cold cathode tubes have mercury vapor in them this is very dangerous if it was broken. Avoided damaging the bulb at all costs as mercury vapor has been linked to brain damage and cancer."
Sounds like fun! I also heard the best way to tell if a wire is live is to lick your finger and touch it. Don't forget to stand on one leg while you do it though! Otherwise you might get hurt.
If you wanna get rich, you know that payback is a bitch
how often do they fail on average?
Once.
I've replaced backlights in powerbooks, both with official Apple parts (it has been
some years since THAT was available) and with generic lamps from third-party
suppliers.
Firstly, remember the lighting uniformity is HARD TO ENSURE. For the thinnest
displays (like modern Powerbooks) it's unlikely you can even FIND a source for the
lamp (2mm tubes are common, the available units are usually 4mm or the wrong length
or both), and if you do find it, getting the foam/mylar/backplate sandwiched
after replacement is going to be a chore. Expect a splotchy result.
The most recent display I had any good luck with was one of the Powerbook 500 series
(about 1995 vintage). That required a little work with a Dremel tool to fit the
available lamp (which was about 5mm too long), and took a bit of care during
disassembly. The plastic display bezel got brittle with age by the time
the unit was both out of warranty and failing to light up.
The 'supported' solution is to ship the unit to the manufacturer for
rebuild. Presumably, they DO have the right parts and a lot of patience.
My advice: pay the $400 (or whatever).
There's a lot less toxin in the lamp than in your last filling. More worrisome is the
wiring to the tube, which wants about 2000V to start. The wires are funny, rubbery
things, possibly a hightech silicone.
One very useful tool was a spare power supply; if your backlight was on a connector,
you can test it on known-good power that way, and an inverter replacement is a LOT
easier than lamp rebuild.
Ok, some comments from somebody who works with cold-cathode lamps.
First the mercury is pretty much a non-issue, it only escapes if you break the lamp and the ammount is miniscule anyway. As long as you are in a well ventilated area don't worry at all.
Second the manufacturer fits high-performance cold cathode lamps, subsituting hobby grade lamps is going to give you terrible colour rendering (I've seen cheap lamps that were more pink than white), and also the light output will be _considerably_ lower.
And last if you use the original inverter you are going to be overdriving the new lamp horribly. So the colour will suffer and the life will be affected (plus the lamps will run very hot indeed).
These are not at all like incandesent lamps, the inverters are tuned to the lamp parameters and cheaper/different lamps are likely to not match the inverter very well at all.
The answer of course is that most of these hazards are serious for people who are exposed to them continuously as a result of work or environment (e.g. asbestos, radon.) Occasional exposure to a small amount of mercury is unlikely to do you a lot of harm; it might even kill a bacterial infection you didn't know you had. Working continuously in an environment containing detectable levels of mercury vapour could be very bad indeed.
Pining for the fjords
Sheesh!
Required disclaimer: When breaking fluorescent tubes, do so in an area with some ventilation. Do not huff the tube. Do not lick the insides of the tube.
Turn the LCD panel, plus an overhead projector, into a projection TV.
(I did it; it actually works quite well. I'm using it as my TV.)
Paleotechnologist and connoisseur of pretty shiny things.
As others have pointed out, the linked article is unreadable, barely informative, and likely to damage the environment and one's health. So here's a better idea: if you want to reinvigorate an aging LCD monitor, why not just remove the back altogether, and mount the panel on a nice white LED lightbox? It seems like it would be a big improvement.
If you RTFA you'll find http://www.lcdpart.com/doc/ccfl.html which lists many 2mm tubes.
The Christian Right is Neither (Christian nor right). See: Matthew 23, Matthew 25, Ezekiel 16:48-50
FYI on Mercury vapor. Generally the vapor comes from a tiny amount of mercury in the bulb that generates the vapor when heated. Florescent lights work in the same manner so if your scared of these tiny bulbs you should be in bind terror of the big tubes. Older bulbs you could actually see a big blob of mercury laying in the tube. The real danger comes if the contents are heated. That's why in the 1800s photographers got mercury poisoning because they heated mercury and waved the glass pane over it to develope the picture. Not real safe. I worked in a shop once that a carpenter built a curing oven and then installed florescent lights. I had to explain the problem and told him to replace them with incandescent bulbs. Mercury is safe enough so long as it's kept cool and you don't come in contact with it. That said I don't like working around the stuff and won't. If any gets spilled everytime the room gets hot you're breathing vapor. The only safe way of handling it is in a closed environment with proper scrubbers for the air.
I don't think I'll be following these instructions for my dimming 17" powerbook. Anybody have any *good* instructions for fixing one of those?
Looking at the text you quoted, I don't see anything terribly "bad" about the instructions.
If you're referring to his spelling, it's fairly clear you are smart enough to have figured out what he was saying, so why judge whether to follow the instructions based on spelling instead of based on your understanding of the instructions?
The primary purpose of instructions are to convey the steps and procedures for accomplishing some task. Spelling and grammar are definitely useful in writing clear instructions, but they are not so critical that a few mistakes necessarily render the whole thing useless (unless the mistakes happen to be "well placed", which none of the examples you've given are).
I get a kick out of the seemingly sarcastic sounding "how do I fix this" things that I see here, and have seen in many other places. Fact is that with "tech" moving at such a pace these days, people (those with lots of ready-cash) are more likely to just dump this stuff into the trash (and landfills) and just go buy something new, rather than fix it.
I have been doing this sort of thing now since something like 1998 with relative ease. The only hassle has been scrounging up the cold cathode tubes that are large enough to cover the screens like the originals. Some will note that these have been conspicuously absent from the after-market parts shelves up until a couple years ago when it became fashionable to "light up" your box with colored lights. You quite literally had to know how to find them prior to this because they did not want them to be found. Any technician worth his salt knew that if you could replace the tube (and it wasn't hard at all to do), you could revive a computer or screen and make some money rather than having the user tossing this item into the landfills and spending whopping amounts of cash on "new models". (Yea, thats an accusation about the major OEM players; NEC, Toshiba and Sanyo; IMO)
As for the brightness issue... If you've replaced the tube and it's still dim, it's nothing more than the capacitors failing on your DC to AC converter boards. The caps are rated so close to tolarance in manufacture that with heat buildup and time, they fail prematurely. I've successfully pulled the boards and replaced the caps to bring them back to life assuming the transistors and IC have not failed. The brightness issue is nothing more than deviating the PWM (pulse width modulation) of the AC out to the tube. This change in PWM changes the resonance for the tube's circuit and hence it's brightness level is related to the PWM circuit efficiency. When the caps become leaky and dry, the circuit can no longer approach its normal or calculated PWM value or resonance, and hence your screen no longer can get as bright as it used to. Color temperature changed screens are the same issue. The cc tube is just more sensative to the current PWM and is lighting up in a particular color temperature; usually a brown or reddish hue.
Theoretically these LCD screens can last for many, many years if you want to simply replace these tubes and fix their circuits when they fail. Based on past history and my direct attempts to get these cc tubes and parts from several OEM's directly; replacing the entire LCD screen as a complete part; at a hefty price I might add; is generally your ONLY choice. More often than not, the replacement LCD panel cost more than the whole monitor did new!!!
I expect however that replacing the cc tubes as a standard repair will not be available because the folks manufacturing the LCD screens seem to control the access and if there is limited or no access to the parts, you only have access to "NEW" screens... or obviously new monitors!
Your market... you decide!!
Cheers;
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Elemental mercury is actualy pretty safe, organo-mercurial compounds are the toxic ones. Of course the popular press has made mercury an emotional issue like nuclear power.
Apocalypse Cancelled, Sorry, No Ticket Refunds
In another 10 years, I expect that they will call out the HAZMAT team for any reported spills of dihydrogen monoxide.
Who wants to bet on the date of the first DHMO call that actually gets a Hazmat team to respond?
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
I work in the fluorescent tube recycling industry. The hazard from the tiny 2mm-4mm back light is negligible. I've done tests with a Jerome type meter, and they read way below (almost non-existent readings) OSHA limits for airborne exposure. OSHA states that you need a respirator for a time weighted average exposure above .1mg Hg/cubic meter. You need to break a lot of tubes to get close to this, probably hundreds of the tiny back light kind. Mercury does vaporize at room temperatures! It doesn't need to be heated!
The type of mercury used in fluorescents is the inorganic kind, which is a hell of a lot less dangerous than organic mercury. Inorganic mercury will be filtered out of your blood and come out in your urine, just like most toxins, but organic mercury is small enough to find it's way into your body fats and stay there for good. Organic mercury is usually what you find in fish.
Mercury Vapor
NIOSH/OSHA Mercury Vapor Health Guideline
Cthulhu Saves.
It's pretty fun to do. A friend didn't want to fix his laptop himself but did want to save some money, so a few of us got togther and replaced his LCD backlight for him. It's really cool to see how many layers of various films are stacked up in there, as at least on this one we had to prety much completely disassemble the panel to get to the light tube.
:)
My friend got slightly the wrong tube length, so the two ends are a bit dark. There's a coupel fingerprints inside the LCD now, and someone's eyelash. If you end up seriously tearing the thing apart liek we did, get some latex gloves or somethign to help with the fingerprints, and try not to shed during the operation.