Step 6: Remove Inverter Board and Connect LEDs

Now that I have replaced the CCFLs, I can remove the inverter board as long as it is completely separate from everything else.  My LED strip runs off of 12VDC, so I had to find a source and neutral point to solder the wires to.  From my experience, this is a very common voltage in LCDs, but make sure to find a 12V source that is off when the screen is off and on when the screen is on or else the LED strips will always be turned on while the screen is plugged in.  Also, make sure it is capable of supplying the necessary current for the LEDs needs.  I wanted to use a fuse on the 12V line to be safe.  Once I attached my wires, I needed to secure them so they don't move around or get pinched during the final reassembly.  I could now continue to reassemble the screen until it is completely put back together.

Hi, first of all thanks very much for your effort's helping other people :) <br> <br>I am a experienced computer maintenance tech, but here in Portugal it's a bit difficult to find parts like this. <br> <br>What I'm searching for it's a led strip for a LED Screen from an ACER ASPIRE 5111. Any idea where to buy this? I have been searching but I'm not sure if my search key's are not very accurate or other reason. <br> <br>Thanks!
Not sure if you already looked at these: http://www.lcdparts.net/XBDetail.aspx?ProductID=3745
Thanks for your comments. I unfortunately do not know where to buy this specific strip. For my project I used a generic LED strip from eBay however I doubt it is small enough to fit into a laptop or that it would perform the way you want. Best of luck in your search.
<p>I think the real hazard would be the broken glass rather than the tiny amount of mercury. I know that mercury compounds can be hazardous but having spilt about a teaspoon worth of mercury on my bedroom carpet as a kid, I never had any affect from it.</p>
<p>Apart from your deep yellow skin tone! ;-)</p>
I was looking to do something like this with a TV my friend got from his uncles camp. I've checked it out and taken it apart, and the screen still works fine just the lights won't work. They slightly come on for about 5 seconds or less then immediately go out and won't come back on unless you shut it off and start over. Kind of like when your fluorescent bulbs are starting up but failing to light. When I took it apart there were about 15-20 very long and thing bulbs. So my question, would this method work on this? It's a 36? inch Polaroid TV.
Spent hours googling for an article like this. Great work! <br>I want to make a daylight visible display for our skateboarding club to use outdoors. These have a brightness of around 1000+ nits whereas normal monitors are about 400 nits. Do you reckon if I carefully inserted sufficient LED strips it could work? Maybe triple strips? I already have an LED power supply and dimmer to take care of power supply if it is an issue with the extra LEDs. I haven't opened a monitor up yet but I have a few available. Any thoughts / suggestions? <br>Please don't suggest buying a proper daylight monitor as they cost BIG money.
I've read the process twice now and there's 1 thing you left out...<br>Where did you get the self-adhesive, cut-to-fit LEDs!?!?! And how much you got &amp; what you paid for it?<br>I've never seen stuff for sale anywhere. and have many other uses for that kind of LED stock in my lab. Please tell us where you got it from!!!
You can get the LED strips from parts express <br>http://www.parts-express.com/pe/showdetl.cfm?Partnumber=073-069
From one of my comments below:<br><br>&quot;I bought mine from eBay. Specifically, I bought these: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&amp;item=200388725627&amp;ssPageName=STRK:MEWNX:IT<br><br>It is actually only 150 warm white surface mount LEDs on an 8 foot strip, not 300 like the ad says later. The 8 foot strip was enough to do two 17 inch monitors and one 20 inch television and have between 1 and 2 feet leftover. I know that you can get twice the length for not much more money. If I had to do it again, I would probably get the longer strip and get them in cool white to try to get a better color and brightness. Just make sure that they are narrow enough to fit into your CCFL holder.&quot;
Wow, that's a great price. I'm going to have get me some of those to see the brightness of the LEDs but I think the Cool Whites would have been better for you. Red is so hard to work around but blue is easier to dial in color-wise.<br>BTW, the ad has been corrected. It now reads 150 LEDs on an 8ft strip. I wonder if you can get 300 LEDs in an 8ft strip...? that would rock. I'd do my laptop right now if I could get 300s.<br>Thanks for the info! And good job!
I really hope this is still open. I have my LED strips. My HP monitor is open and disassembled. What I need to know is, where in the world do I solder the LED strips to the power board? The invertor board is part of the power board. Can I just go directly from the 12v plug in if I dont care about having to unplug the monitor to shut it off?
Assuming that your LED strips are rated for 12v, you should be able to draw power straight from the 12v supply as long as it can supply enough current. The LED strips should draw vey little current though. <br><br>You will have to either unplug the monitor to turn off the backlight or you can wire a MOSFET up as a switch to control it. The way I did this was to use the wire to the LED that turns green when the monitor is on as the control signal to the gate of the MOSFET. This makes it so that the backlight is controlled by the single LED on the front panel. If you are not familiar with electronics though, I would not recommend this as it varies for each monitor.
Yes, my strip is 12v. So in theory, I should be able to connect it to any place on the board that has 12v coming through it. I did make the mistake of connecting it to the 12v power cable. Whole strip lit up and immediately went dead with only a single LED lit lol. I dont know if the strip was bad, or if I fried it. Basically just used alligator clips to jump to the monitor power cable and straight into the wall.
Your write up is good, could you provide a wiring circuit diagram to show where to find the 12vdc supply point on the mainboard. tq.
The 12Vdc supply point will vary depending on the main board circuit, which is why I didn't provide the wiring diagram. You can look at the power supply first to see if it is labeled with the voltages where the connectors go. That is where I pulled my source from. Otherwise, you will need to determine where the supply is on your particular board and take the appropriate voltage from there.
Thanks cheeyah. My lcd tv output supply is a 24VDC. I'll connect the led strip to the 24VDC / Grnd. C if it will work.
Tq cheeyah., ur reply appreciated. My lcd tv supply is 24VDC, thus I'll connect the led strip from there. C if it will work.<br>
This is an awesome instructable! I am working on a project similar to this, but I need a dimmer hooked up to the LED array. Have you ever come across anyone doing anything similar, or have you maybe done it yourself?
I would recommend using a PWM to do this rather than trying to vary the input voltage. This usually provides a better and more consistent dimmer function than varying the voltage.
brilliant!<br><br>i have 3 15&quot; monitors i may try this with, either this or they get repurposed into something else, what, i dont know.
out of curiosity, how well would you think this would work on a 40&quot; tv?
I would guess that it might be too dim if the screen is only edge lit. If you can get bright enough LEDs and can fit enough in the screen, it should work just fine. I have seen some larger screens that have backlights along the edge as well as behind the screen, in which case you should get enough brightness. Let us know how it comes out.
Interesting idea. I wish i had seen this before i trashed a not-functioning Insignia TV. Two different TV repair shops couldn't make it operate. The TV would not start up. The red power-applied light kept flashing and would not change to green to indicate power on. How do your get the basic TV/monitor to function. There is computer-controlled circuitry inside those monitors. How do you bypass that to at least get the unit to turn on and send signals to the panel for the LEDs to illuminate?. <br><br>Regards<br><br>
Insignia is Best Buys &quot;House&quot; brand. Why didn't you just take it back to the Geek Squad and let them send it out to be reworked? If it was under warranty and they couldn't fix it, they would have replaced it at no cost to you or you would have gotten an estimate for repairs then a follow up call to let you what they found and what the final bill was going to be. At that point you could say &quot;don't bother with it&quot; if it was too much or (like what happened to me) they call you and let you know that its still under warranty and will be repaired and sent back to the store in X number of days. They have rebuilt my Samsung 22&quot; 2ms HD monitor twice now and it cost me $0!<br>Too bad you trashed it.
That sounds like a worse problem than just a backlight. Probably the power supply...
Once I had the same problem and it turned out that the fault was in the internal switching power supply: one of the capacitors/diodes was broken. The actual fault was in the design that prescribed an item with a too low capacity for the job.
I had monitors that turn on and display pictures. The only problem was that the backlights would not turn on, so the displayed picture was not visible. This can be checked by shining a flashlight into the screen with something playing. If you can see a faint picture, it is the backlights and probably not the power supply. Any time I have had problems with getting a monitor to turn on, it was a problem with the power supply.
Thank for your answer. <br>The inverter board and main board are separate . <br>They connect with wire cable. <br>The main board supply power (DC12V)and one channel control signal to inverter board by wire cable. <br>The control signal can controllable inverter board let CCFL bright or dark and inverter board respond signal to main board by control signal channel. <br>I mean that main board must have respond signal from inverter board. <br>If main board can not receive the respond signal then main board not working. <br>Have some way can bypass the signal let main board working without respond signal.
So if I understand correctly, your inverter and main board a separate but if you disconnect the broken inverter board from the main board, the main board stops working as well. What you want is to send the signal from the inverter board back to the main board so it keeps working as well? I have never come across this problem before, so I really can't tell you exactly how to fix it, but I will try to help. One quick note though: You shouldn't try this unless you are comfortable modifying and working on electronic equipment. Attempt this at your own risk.<br><br>First, does all of the main board not work or just the power to the inverters? If the main board continues to work enough to produce power and turn on the screen without the backlights, I would try taking power from a different place than the inverter power.<br><br>Second, if the main board does not work at all, do the boards work if you leave the broken inverter in place with the CCFL's disconnected? The backlight won't come on, but does the screen still show signs of displaying a picture when you shine a very bright flashlight directly onto it? If it does, I would try leaving the broken inverter in place and just not connected to anything but the main board. You just have to find a source for your LEDs then. The original inverter output is NOT suitable for powering LEDs.<br><br>The last thing I would try, which may completely ruin your screen if done incorrectly, would be to find out what the signal back from the inverter board to the main board is and try to replicate it.<br><br>I hope this helps and I'm sorry I can't answer your question more exactly, but I have never seen this problem before.
It could also be just a &quot;Power Good&quot; signal from the closing of run circuit after the start-up of the CCFL (Like the Power Good pin on all power supplies produced for the last 10 years. That's just a 5V reference signal that prevents you from starting the mobo without a CPU installed).<br> If he does what you've suggested and it doesn't work, he may just need to &quot;Jumper&quot; the circuit at the motherboard.<br> Best bet might be to start out with a schematic diagram of the unit in question. You can generally find it on-line by google searching for the model number and manufacturer's name Or just head to their website and look in the Support area. Sometimes if you call them and ask where you can find this information, they will bend over backwards to help you find it.
would this work in a laptop?<br>my laptop's screen works but I was wondering if the brightness could still be changed. I know very little when it comes to the individual components, but I still want to fix a laptop I found at a thrift store for word processing, maybe some PSX 7 GBA emulation...
As long as it's not something like an Apple MacBook Air, it should work. But, like he said, know the point you drawing power from! If you can't figure it out or find a schematic that tells you, you might not want to try this. 12V is a common voltage in newer LCD Monitors but laptops are unique.<br>Laptops are very proprietary and run at strange voltages. Just look at what it takes to charge them. Most are 19 Volts and about 6 Amps-ish (mines a little older and this is what it takes to charge and run mine. I can't even use the adapter from my other laptop to run this beast! It's just too weak at 70W) and it takes 110W.<br>All I'm saying is knowing is half the battle. But if you don't mind risking it, try it! You may just get lucky!<br>Plus I bet the battery will last a lot longer with LEDs and not that inverter eating up battery time and wasting most of that juice as heat!<br>Let us all know how you're doing on it and if you're successful or if you get stuck and need some suggestions!<br>Good Luck!!!!
I don't know if the LEDs would fit in a laptop. I am guessing by the thickness of most screens, you would have trouble, but I have never had a laptop backlight go out so I haven't tried it yet.
am an electronics hobbyst and i apreciate your instructable because sometimes i want to repair a Lcd monitor but when the problem is in the Inverter section for me the Game is over!! Cause where i live : Guatemala, there is no a supplier for this electronic parts. THANKS!! and Greetings from Guatemala!! sorry for my english..<br>
I repair my old 32&quot; LCD, it CCFL inverter is fail so I use LED change it. <br>but the inverter board connect with main board . Have some signal contact each other.? <br> My question is when the inverter remove then main board can not contact inverter signal so the main board not working . <br> Have some way can by pass the signal? thanks
I'm sorry but I am not sure I understand your question. Are you having trouble with the inverter board which is part of the main board? From what I am getting, you are saying that the inverter is causing problems with the main board. If this is the case, you need to find the fuse for the inverter part of the board and remove it. This will not allow power to pass into the inverter. If I missed the point of your question, I apologize, and please tell me what you actually meant.
Very nice instructable, I already was looking for a way to repair my old first LCD, I was quite sure that only the backlight is broken.<br> Did you ground the inverter somehow? I imagine it could be quite dangerous otherwise because of the high voltage.<br> And do you know certain ways to find the 12V power supply in step 6? I know that every monitor is different and I didn't look into one yet, but I already saw some circuit boards and I'm not sure if I could find a point to get special voltages from, at most the grounding maybe.
I actually took the inverter boards out rather than grounding them. I think if you ground them you will probably damage your power supply. On the one that I couldn't remove the inverter board because it was the same board as the power supply, I found and removed the fuse for the inverters. <br><br>I took voltages from where power originally went to the inverters. Since those ribbon cables are no longer needed, I used the wires that I needed and removed the rest. The only bad thing about this is that in some monitors, these do not turn off when the monitor is turned off. I am working on a modification for monitors where a switched line cannot be found.
Aha, thanks! So the inverters normally have a 12V-supply? I'm sorry if this is a dumb question.
It is not a dumb question at all. All of the ones I have worked on have a 12VDC supply. They also usually have several other lines, so be sure to check which one you are using. From my experience, they usually have a 12V power supply, 5 or 3V control and Ground.
Maybe the leds should be uncleared with sand paper.<br>
If you like what you see, please vote for me in the LED Contest and the Back to School Contest. Thanks!
great idea!
I readily welcome all feedback, comments, and suggestions for how I could make this Instructable better. Thanks!
Where did you buy the LED strips from?<br><br>I have an old monitor this could help resurrect since the CCFL's just died one day.<br>
I bought mine from eBay. Specifically, I bought these: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&amp;item=200388725627&amp;ssPageName=STRK:MEWNX:IT<br><br>It is actually only 150 warm white surface mount LEDs on an 8 foot strip, not 300 like the ad says later. The 8 foot strip was enough to do two 17 inch monitors and one 20 inch television and have between 1 and 2 feet leftover. I know that you can get twice the length for not much more money. If I had to do it again, I would probably get the longer strip and get them in cool white to try to get a better color and brightness. Just make sure that they are narrow enough to fit into your CCFL holder.
This is an incredible idea. I had no idea you could buy LED's in strips like this, Or that you could cut them.<br><br>Is it possible to buy LED's with unfocused lenses, With enough Lumens to equal the amount of light the original ccfl created?<br><br>Im sure the focused lenses are the cause of the bright spots, And with enough smaller LED's being unfocused, You may actually be able to simulate the original light levels.<br><br>Great idea. Ive been trying to solve this problem for years.
I have never seen them with unfocused lenses because they always have the junction protected by the lens. That is a great idea though if you can find them. I thought about adding some kind of diffuser but couldn't think of what to use that wouldn't dim the LEDs enough that the screen would be too dark. <br><br>If one could find a strip with LEDs closer together, the bright spots could also likely be eliminated. I believe they happen because instead of a fairly constant bar of light like the CCFLs produce, the LEDs are point lights. I unfortunately couldn't find the strips with LEDs closer together though. If I ever come across them for a decent price, I will try some. <br><br>Also, if you have any experience with making circuit boards and soldering surface mount components, I don't see why one couldn't make their own LED strip, but it would be a lot more work.

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