If you are a student like I am, sometimes it just too expensive to buy new hardware. And why should you? There are many companies, faculties that throw away used non-working equipment. Here I will show you how you can repair used LCD monitors practicly for free.
In the past year or so I managed to repair about 50 LCD monitors out of 60, that I sourced around my town. From my experience I can tell you, that you can have a working LCD monitor in under 20 minutes practicly for free with no profesional tools required.
  1. How an LCD controller drives an LCD glass. Nishant Kaundal, Kushal Kamal, Siddi Jai Prakash, Freescale -November 24, 2013. Then the LCD unit glows, otherwise it remains off. To understand the working of an LCD controller driving LCD glass in detail, firstly the basic understanding of some important terms is required. Low power filter.
  2. The pinout is not easy to figure out. If the original laptop is still attached to the LCD, one can measure the voltage on each pin on the backlight controller board and simply replicate that.
LCD monitors are not that complicated as some of you think. They are made from 4 parts: LCD module, main board, switched regulated power supply (SMPS) and button board.
From my experience, the main faults are:

HDMI+DVI+VGA Controller Board Driver kit for LCD Panel LTN156AT09. Horizontal driver inside your LCD is still work, If it does not work our kit can not fix it. One of the more common problems with LCD displays is the potential for stuck or broken pixels, where the pixel either does not receive a voltage and remains black, or does not respond to voltage.

- 10% faulty inverters
- 5% other issues (faulty buttons, main board, LCD module, CCFL, FETs)
Fixing this problems is very easy and very cheap. You can get capacitors and buttons in your local electronics store. Inverters are sometimes a problem to get, but ebay will probably have the one you are looking for and its price is around 5$.
There are many different brands of LCD. The most common are Samsung, LG, HP and Dell. And they are all more or less the same. You should also know the fact that many LCD modules are compatible. For example, I replaced an LCD module from HP to Samsung and it was a perfect fit. This is because the modules are basicly same dimensions and same LVDS connector for all types. Sadly it is not the same for mainboards and SMPS. But hey, SMPS can be fixed and main boards and LCD modules are very rarely defective.
LCD issues can probably tell you which part is faulty. So lets go to the symptons:
1. LCD lights up for less then 5 seconds, then it goes blank (check if you can see picture):
- it could be dead capacitors on the inverter low voltage line (high probability)
- it could be a faulty inverter (low probability)
- it could be a faulty cold cathod flourescent tube inside LCD module - CCFL (very rare)
2. LCD power LED blinks but monitor does not light up:
- it could be dead capacitors on the 5V logic line to the main board (high probability)
- it could be a dead LCD module (very rare)
- it could be faulty capacitors on SMPS (high probability)
- it could be defective main board (low probability)
- flex cables in the LCD module have a weak connection (very rare)
4. LCD turns on, backlight turns on, but gray or white screen appears:
- poor connection of LVDS cable (very rare)
- dead capacitors or inverters (high probability)
6. LCD works ok, but sometimes it seems like that buttons are pressed for no reason (OSD menu appears):
- faulty main board (very rare)
7. LCD appears to be completly dead (no LED signal light)
- it could be faulty capacitors on the 5V logic line (high probability)
- it could be the fuse on SMPS (rare and probably for a reason)
- it could be faulty main board (very rare)
These simptoms can tell you very much of your fault. Now lets beggin with our dissasembly... I had a 17' Samsung monitor, with an issue number 1.
LCDs are encased in plastic housing which is hold together with few screws and a click sistem. This is probably the tricky part of disassembly. When you remove the housing, carefully remove the LCD module. But before you proceed, unplug the CCFL cables from the SMPS board that hide behind a metal shield.

Metal shield
Unplug these cables

When you are finished with CCFL cables, unscrew the LCD module and carefully unplug LVDS cable from the module. Now you have a full view of the main board and SMPS.

BE CAREFULL! The big capacitor on the mains voltage line on SMPS could still be charged. So make sure you discharge it before proceeding.
Now that you are done with that, unscrew the SMPS and look for faults. In most cases a dead capacitor is visible. But if there is no visual sign of a fault, replace all capacitors on the SMPS. This will fix all your problems in most cases. I also recomend that you replace all capacitors on voltage lines on SMPS even if they appear to be good.

Faulty capacitor here is visible

Next use your multimeter and measure the resistence of high voltage side of the inverter. In my case the high voltage side of the inverter shows about 620 Ohms on both of the inverters. Because values on the both inverters are the same, I can assume inverters are OK. But if the value varries between the two inverters, the one with lower value is faulty. So you will have to replace it. You will most likely find inverters on ebay.
FETs can sometimes be faulty too, but it is very rare. If you can see cosmetic fault of overheating, try replacing them too.
SMPS botton

High voltage side of the inverters

Button board

When you are done, put everithing back together, except for the plastic housing. Now you can plug your LCD to the mains and see if you get a NO SIGNAL screen for more than 10 seconds on your LCD.

LCD appears to work :)

Now that everything seems to be OK, put the plastic housing back on, plug your LCD to a computer an leave it running for an hour. If no problems will accour. Then the LCD is fixed :)
Now you have a new LCD monitor for 0.15$, the cost of a capacitor

If capacitors are the case, the success rate is allmost 100%. If you diagnosed other faults, like main board fault, LCD module fault or CCFL fault, the cost of the repair is too high and you will have to search for another LCD monitor. Don't forget to store your working parts from a busted LCD monitor, becase they might come in handy if you try to fix some other LCD monitors.
Here you can see some other pictures of faults:
Faulty capacitors
Inverter from an 19' Samsung, faulty high voltage side CD
Faulty main board - no visible sign of a fault. Tried to change voltage regulators but no luck...
If you end up with different working parts of different LCD monitors and all the same size, lets say 19'. With a little knowledge and some spare time, you can put together a working LCD monitor. But you will have to make your own housing, becase the SMPS and the main board will probably not fit in the original housing. That's how I made a 19' LCD monitor in my workroom, made from a 19' Samsung LCD module and button board from Samsung, SMPS from Dell and main board from HP monitor. But this will require some more electronics skills, because SMPS and main board power connector is in most cases different.
I hope this post helped some of your problems out there. If you have any additional questions, fell free to contact me by e-mail.

Editor's Note: When a standard LCD controller is not suitable for a particular display screen or application, OEMs must choose between custom designing their own, or hiring a company that specializes in building custom LCD controllers, such as Digital View. In this article, Digital View explains how to approach a custom LCD controller project, and why even experienced engineers sometimes prefer to outsource these designs.

Lcd Controller Driver Board Not Working

View Digital View SVH-1920 LCD Controller Board full size

For more than thirty years, major companies have been making enormous investments into development and manufacturing of advanced LCD panels. The quality, reliability, resolutions and size have continued to increase every year, while the costs have dramatically decreased. All of these issues -- coupled with the benefits of low-power consumption, small physical size and the general 'sexiness' of the LCD -- make it very desirable to OEMs and integrators to incorporate into a wide range of products.

All LCD based products, with the exception of some embedded systems, will require a controller to provide a suitable interface and very often a range of display functions critical to a project. As this is a key part of a display system specialist companies have emerged supplying controllers thus providing companies with the opportunity to make or buy, the choice is available. To adequately make this decision, there are quite a number of issues to consider:

Decisions to be made
Among the initial decisions to be made is to define what the controller is expected to accomplish and under what conditions it has to perform - other constraints like the PCB footprint and costs will come later in the project. Some of the primary decisions to be made will include what is the maximum resolution to be displayed and what input interfaces will be needed. The supported input resolution is not necessarily limited to the displayed resolution of the LCD, as current display controllers usually support up-scaling of lower resolution data to match the LCD, and some can even support down-scaling where complex algorithms are used to reduce the resolution of the data to fit the available display format of the LCD. Supported interfaces may cover a wide gamut of choices, including support of industry-standard ARGB interfaces for PC inputs, composite and S-Video connections for low-level video support, higher definition video via analog or digital component interfaces and Digital Video via DVI interfaces.

View Figure 1 full size

Fig. 1 shows the major components that comprise the first 80% of the steps involved in a flat panel controller board design.

Selecting a Controller

With some idea of the basic criteria in mind, the next element to be considered is selecting a suitable 'engine' to provide the intelligence to accomplish all of these tasks. Controller engines are typically high density single-chip single-purpose devices built by one of a small number of specialized developers. Primary names in the industry include companies like Genesis, Pixelworks and ST Micro. These companies each sell one or more specialized controller chips designed to be the heart of the analog controller design. Controller components vary considerably by features, flexibility, complexity, and of course cost. Considerations in making a selection must include not only reviewing the performance and features of the chip but also looking at the development environment and the support available. Many of the vendors offer a minimal reference design to speed the hardware development and a basic software development toolkit. Development toolkits typically provide basic boot-up code and a utilities package suitable to get a basic display on the screen, but considerable development will be needed to mature this into a complete product with appropriate features and stability. A final consideration here is development support. These components are developed by manufacturers envisioning sales to set-top box manufacturers, high volume desktop monitor manufacturers and the like 'so, they may not be too interested in providing support for someone building a few hundred products a year. In some cases, manufacturers impose minimum purchase requirements before any support is available.

With the chosen chip set and a definition of the input ports and desired display resolutions, there is still much more work to be done. Depending on the inputs being supported, the design will need an appropriate analog-to- digital converter with performance appropriate to the application to manage the inbound ARGB signal, DVI receivers and other decoders. Decoders and receivers mean input ports to the controller, and with that come the liabilities of ESD and EMI, plus the necessity of providing protection against the ports being connected incorrectly (over voltage, reverse polarity protection etc.)

Lcd Controller Driver Board Not Working On Ipad

Lcd Controller Driver Board Not Working
< PreviousNext >

Lcd Controller Driver Board Not Working On Computer

Most Commented