LCD monitors are actually relatively simple devices they have no need for a on board processor or at least not a big one nor do they need a tuner let alone a digital tuner unlike LCD TVs.
First lets go over what you will find when you open up a LCD Monitor. First right under the cover of the LCD monitor you will find the PCB(Printed Circuit Board) typically with magnetic shielding separating the display screen from the PCB.
Often you may find a second smaller PCB inside your LCD monitor under the cover near the power inlet port. This PCB rarely goes bad. The same goes for the components on the board, and this PCBs job is to generate the DC voltage used throughout the secondary PCB, which has the microprocessors and IC’s on it. These control the refresh rate resolution and more of your LCD monitor. Suffice it to say this little PCB is the POWER SUPPLY use caution in removing this PCB or disconnecting it from the other Main PCB.
On the PCB you should find 2 transformers. These will usually be near each other and are usually easily identified by the number of pins, the wire coil in the center of them, and the yellow plastic covering them. Near these 2 transformers will be wires typically in a 2 wire plug form plugged into the PCB these 4 wires supply power to the florescent back lights inside the display area of your LCD monitor.
Now the Display area, the screen itself is usually one complete unit which can be broken down into smaller parts, 1 plastic protective film over the top of the LCD screen, then a few layers of magnifying films to sharpen the image, and finally at the bottom of these multiple layers. You will find the LCD itself in the form of a hard glass piece about 1/8th of an inch thick.
Inside of the metal plate holding all this together either on the top and bottom, or on the sides will be 2 florescent lights running the length or height of the screen. The LCD screen will have a ribbon running through the back of it and down to the main PCB.
In order to separate this part you will have to disconnect this ribbon without breaking it. Gently pull the little plastic tabs on each side till they pop out then the ribbon should be loose. There is a set of 2 tabs like this on each side so you can pull the ribbon from whichever side is more convenient.
Now that you know what to expect inside of your LCD monitor, let’s move on. What you need to or want to take apart is going to depend on the type of issue your having.
If your LCD monitor has a half lit screen 1 of 2 problems you face. Either the transformer which generates the power cycles for the florescent on that side is burned up, or the bulb is burned up.
If looking at the bulb you don’t see any signs of blackening. It’s likely going to be the transformer, but your lucky you can easily find this out. Assemble or leave assembled the power supply PCB and the main PCB then plug the bulb that wasn’t lighting into the other transformer plug.
Ensure nothing metal contacts either PCB or anything on it. Now if your comfortable doing it this way you can power up the monitor. If the bulb lights it’s the Transformer. If your not comfortable, then reassemble everything after swapping those 2 wires.
If the bulb is bad, you will have to find a site that sells custom bulbs it has to match the rating of the one you pulled, “good luck”… Two places to keep in mind are the Vendor of the monitor, and possibly radio shack. Radio shack doesn’t seem to have much in stock anymore.
If the bulb is not bad and it is the transformer your going to need a soldiering iron, take the main PCB out trace the pins on the transformer to the back of the PCB and remove the soldier on them. Heat one pin at a time getting as much soldier as you can off of it then with needle nose pliers you can pull it through the PCB.
Once this transformer is removed take it to Radio Shack and they may be able to match it up for you. Otherwise if you can read the numbers on it, run a google search for it or contact your monitors vendor it’s going to need to be replaced.
Next problem, cracked screen! It’s hopeless throw it away go get another one screens actually cost nearly as much as the whole unit.
Black screen but the power light comes on and turns green giving the go?
If your having this issue it’s most likely going to be both bulbs are bad or both transformers though this scenario would be rare. I’ve never even seen it before, but it could happen… The easiest scenario here is to simply take a 50/50 guess the transformers don’t cost much. If you can get them just buy both and put em in. Still no display? Now get bulbs especially if the bulbs look burned.
No power light?
Get a multimeter and check the wall receptacle or change receptacles. Still no power?
Check with the multimeter at the inside of the power supply right off the main plug for 110-120V AC. If you still have power most likely the “Power Supply” has gone bad. The capacitors or the transformer are the most likely cause for this situation. They are cheap, so replace them all with the same rating caps and transformers.
Multicolored display psychedelic!?
Toss the monitor as the only causes for this are nearly unrepairable none the less I will explain why it would do this.
The single most probable causes here are defective ribbon which you could possibly get from the vendor. The number of pins and size vary from vendor to vendor. So it will be hard to replace if your vendor isn’t willing to sell you the part.
The only other reason it would do this is that there is a microscopic crack somewhere along the surface of the LCD. This would cause the electrical signal to break down. The electrical signal generates color through your Liquid Crystal Display if the Conductivity between two crystals is compromised, it has a chain effect moving along that line. The amount of voltage/Amperage defines the color displayed by each Crystal. The circuit can’t be broken the only way to repair this is to replace the LCD itself.
I hope you realize the importance of recycling now. Don’t throw those LCD monitors away! Bring them into a PC recycling shop, keep them for parts yourself, or give them to some one on craigslist. just don’t throw them away.