I’ve been thinking about converting my lcd 15″ to a transparency for projection, so this dissasembly has been very useful. Does it matter in making a transparency out of one of these LCD monitors if it is TFT or EFT(?)? The monitor itself is an older DELL lcd.

Interesting. I recently had my 17″ LCD fail and have been keeping it around on the off-chance that I might be able to do something about it… Looks like now I can!

That is why I read hackaday. You just can’t beat this stuff. Need to do some dumpster diving and find me a broken LCD.

I personally have replaced many many backlights that were not indeed bad. I have read that like 80% or something of backlight failure is the bulb, not the inverter. From my experiences, this is completely WRONG. a good way to test to see if you have a working inverter is to take a plastic bic ball point pen and while the computer is on touch it beween the red and white wires (on the molex). If your inverter is good, it will spark. If you shock yourself though, it feels like someone taking a needle and poking it all the way into your finger to the bone. Keep that in mind.

My reccomendation, buy an inverter off ebay first. They are about 12 dollars, and you could always sell it if that does not fix the problem. If you try this method, you will probably break the old bulb you have trying to replace it, and manage to get some ghetto action goin once the new light is back in.

good luck folks.

-Tired2

i replaced the inverter on a gateway 18″ lcd with no problems at all…a few screws, a couple of wires that plug in (no soldering), and it was good to go. i ordered a replacement inverter from a 3rd party vendor. i picked up the LCD for free since it was “broken”, and paid $85 for the inverter…not a bad deal.

i also have a friend who built an LCD projector. the brightness is always a problem, even with a 400Watt high intensity discharge pulse-start bulb.

I got a 17″ IBM TFT flatpanel from the trash, and it was just the backlight that was bad. It had 4 CCFT’s in it. I left the CCFT’s and the backlight plane in place, and dropped in a $12 inverter made for a green glow tube for a PC case, and use that to drive one of the CCFTs. It’s bright enough for most uses. I need to get three more inverters and switch them off and on to be 4 levels of brightness.

the inverter needed 12v, so i scrounged that from the line for the 12v fan in the monitor.

The tubes in it were fine, the backlight assembly was fine (not that it can really break)… just the inverters/dimming circuit was bad.

A cheap, quick fix, and it runs great! :D

first, do cold cathodes really contain mercury? Second, the inverter thing is the same with computer ones (like for case modders). Third, you don’t have to dremel, most of the time glue is the only thing keeping it in the tube.

And last, yo ucan do this same thing for scanners.

Some vital advice I haven’t seen would be how to tell a failed inverter from a failed backlight. What kind of failure pattern would you see from each one?

The dead 17″ I mentioned above would flicker briefly and faintly, mostly in the lower-right, before going completely black. Could that be a bulb problem, or would a faulty bulb simply fail to light entirely?

http://www.allelectronics.com/cgi-bin/category.cgi?category=search&item=FL-122WH&type=store
there’s a white cold cathode kit that’s probabaly suitable for hacking.

benji, there is an enable line and a brightness line on most inverters.
the enable on mine was tied high and the brightness tied low for max bright. So there were 4 wires on the input to the inverter.
you need to google the part number on your board to find the pin out.

#13, my guess is they contain mercury vapor.

#20 adrian, my guess would be that the inverter and backllight are OK. lines usually indicated a bad panel. backlight and inverter problems usually manifest as a very faint image on the screen. But I can’t see what you’re working with so I can’t tell for certain.

I’ve done a repair similiar to this but I used a DMM find the +12 and then looked for the line that changed state when the backlight was turned off and on use of an oscilloscope or logic probe can make this quicker work.
On my display this was done by the controller board pulling a pin low which would turn on the backlight inverter a high signel also was avilible from the status LED since it was driven by a simple two transistor circuit that inverted the low signel off the same pin on the controller IC.
I then simply soldered in the new connections use some plastic stand offs to mount the new BL inverter board.
A little work with a DMM and a few parts was all it took to adapt the new inverter board and have all standby functions work.
The display still works today better then new since the new inverter board runs cooler then the original.
Though on someone posting the backlight color changing that sounds like the CF tubes themselves are dying or are not being driven properly.
Another possible repair to a broken LCD might also include an array of surface mount white LEDs mounted to a long and thin PCB carrier which I might try if I have to fix another dead flat panel.

I recently had my gateway laptop lcd died on me. I was able to connect to another monitor and i was able to see the screen when i have a flash light on it. What do you think i should get?? An inverter. Thanks

Hey, I have an HP Pavilion ZV5000 with a cracked LCD screen. I’m not sure how it managed to crack… but if anyone is interested in the computer or the LCD screen ( I dont know why you would be interested in the screen, but hey.. who knows) email me at Kandy06@sbcglobal.net. I don’t want a $1,500 paperweight. :|

Response to Jason (#29)

Jason, I had the exact same problem with my Dell laptop. I’ve been using it with another monitor hooked up to it for the time being. The estimate I got for repair was almost $500. At that rate, it is worth it to me to try to fix it myself. Did you figure out anything yet or get any responses?

hello everyone…

I have ACER AL1511 BM 15″, it was send to me by friend of mine he was going to throw it away, the problem with this LCD is when you turn it on I could see ACER logo and than goes dark and than show something again but than back to darkness and stay like that but If I turn off the LCD and on again I see ACER logo, and Windows but back to darkness.. I open the LCD and I check with my multimeter to check if there any volt from PSU to lamp and only give me volts when I turn the LCD on and than when goes back to darkness than I get zero volt on my mulitmeter, I figure the lamp are fine or going dead or is the PSU… I read some of comment from other users, like “inverter”.. well let see what other people has to see about this LCD…
thank you for your time.

My six year old Dell Inspirion 7500 LCD screen has developed a pink screen at startup. It clears up after about 10 to 15 minutes but seems to be getting progressively worse…worse meaning a more intense pink covering more of the screen. What to expect next and is this a problem worth fixing? Budget is tight and I am not a techie. Any suggestions?

Hi all.
I purchased a used NEC 2010x 20″ lcd. When I power up the lcd there is a high pitched wine coming from the left rear of the monitor. When the lcd goes into power-saver mode the whine becomes lower pitch but is still there. When I adjust the size of a window with the mouse the whine also changes pitch! BTW Picture is awsome.Is my lcd about to blow up? I am far from an expert but don’t mind getting my hands dirty. Any suggestions will be appreciated.

Yes it is hard to figure out Inverter in LCD Monitor. On laptops is easy. Mostly it is in back of the LCD or under power button bezel . Why dont you give search of monintor inverter in google. You migh find many pictures you can match with.

Hello,

In an effort to find the backlight for a Dell E151FP monitor, I mistakenly cut 3 plastic strips that go from a circuit board to the LCD. At first I thought these were just adhesives, keeping the LCD secured to the frame.

I am wondering if I have permanently damaged the unit or if I can somehow glue or tape this back together. Any ideas or comments appreciated.

I am attaching a picture of the image as well. I would very much appreciate you advice so that I know if I should continue with my backlight replacement project or if I have ruined the LCD.

Thanks,

Please see pictures here:

http://70.190.233.56:8088/images/lcd1.jpg

http://70.190.233.56:8088/images/lcd2.jpg
http://70.190.233.56:8088/images/lcd3.jpg

Sincrerely,

Am I screwed?

Seems you have lamp issue. I have seens lot of CCFL . Laptop LCD backlight issues ( Lamp issues
Dell inspiron 8100 / 8200 / 8000 series . Mosly SXGA Tx38d99vc1caa LCD comes up with reddish tint and lamp blows up. But as laptop model it self is old now i will always suggest to check inverter voltage. Here is some more information about back light issues
http://www.247laptoplcd.com/faq.html

My husband has a Gateway Laptop. He recently purchased a 19″ Flat Screen Monitor. He is trying to connect the two together, and use the flat screen exclusivly. So far, no connectivity. How does he do this? It’s not working!

Inverter of Display (Bulb?)

I have a flickering backlight that has some other consistent symptoms of note.

Physically tapping (and perhaps banging after a second cup of coffee) does affect the backlight. It will flicker

have HP Pavilion zv5267la 15.4″ LCD, it was send to me by friend of mine he was going to throw it away, the problem with this LCD is when you turn it on I could see HP logo and than goes dark and than show something again but than back to darkness and stay like that but If I turn off the LCD and on again I see HP logo, and Windows but back to darkness.. Lamps ok, Buy a new inverter result is same back to darkness, Help…
thank you for your time.

I have a dell rackmount keyboard monitor tray for a server rack. However the monitor has gone dead and dell will only sell the entire tray and not just the monitor. so i replaced the backlight, and that didnt solve the problem, so Im thinking its the inverter, however, I cannot find the inverter for this particular monitor ANYWHERE!! Any ideas? Part: 6H507 Model: SL340. And the only numbers on the inverter are, PK07V00500, LI-1031 Rev. B, and C2920127G…Thanks for your help!

Just wanted to give everyone a heads up. I believe Samsung has an issue with the 740N LCD, bad inverters possibly. I have recently had a failure trend develope and believe it may be a manufacturing issue. Description when my tech picks them up is always backlight is not on. Anyone come across this too please let me know?

I am fixing a hp pavilion 5120 laptop. when i start up the computer the hp logo comes on and there is a pink tint. after about 30 seconds the backlight goes out. pc is still functioning, but unusable b/c you can only faintly see the image. i am not sure if i should change the inverter board or the bulb or both. i am more of a programmer than anything so i don’t have much experience with soldering. can anyone help?

An actual answer from someone! thank you hitek!

I have a Toshiba Satellite 1805-S274. The LCD will display for a period of time and then go ALMOST completely black. I can see a very faint image on the screen. I tried the “Fn + F5″ key and the screen will usually come back for a few seconds but back to the same state of almost completely black. Other sites point to the inverter board. Any suggestions?

Thanks

Worked! Thank You.

Hey guys,

My monitor has been dying & naturally I tried to cycle the power until the light holds up as it usually just blinks and immediately dims on its own. This has been working but just recently the problem got worse to the point that no matter how many times I cycle the power (like 50+), the light will no longer hold up. I then got creative & tried this work-around which seems to work so far:

Turn ON the monitor, look very hard as you try to adjust the brightness all the way down to “0%” using the monitor buttons. Then turn OFF the monitor, and then turn on back on. Bingo! That worked for me. I noticed that the brightness has an effect because after that when I tried to reraise it up to “100%” the light dimmed to black again! Still I can work with “0%” – probably better for my eyes anyway.

Hope this keeps you guys from messing with mercury vapors.