2. Assemble and Test the LCD Screen
This is what the front of your screen should look like:
And the back:
For now, leave the factory protective plastic cover on. On the backside you will find the only connector you need to be aware of, a mini-LVDS female that is used both for input and power supply (highlighted in red). Be very careful as you manipulate the screen because it is rather fragile and you don’t want to end up with a cracked panel like I did.
If you are curious, this is what a cracked panel looks like:
Next, let’s inspect the controller board. The board pictured here is an NT68674.5X. Using this exact model isn’t a requirement as long as you have a datasheet for the board you bought (ask the seller).
Here is the front of the NT68674.5X board:
And the back:
And this is why datasheets are useful:
Connecting the board to the display will either be the easiest step in building your HMD or the hardest. To make it easy you should buy the LCD screen and the controller board from the same seller and ask them for the proper LVDS cable. I am going to assume that is what you did, if not I recommend you reach out to someone with an electronics background and plenty of soldering experience to help you build this cable.
With the LVDS cable at hand, you must then consult your board’s datasheet to find the correct way to connect it to the display. Be very careful as some boards will allow you to connect the cable backwards which might damage the display, the board or both.
On the particular board pictured here, the LVDS cable must be connected to two distinct male connectors, one on the top right side of the board for data and a the red connector on the bottom right for power (I presume).
Be very careful when connecting the LVDS cable to the screen. The male connector is very small and it is hard to tell which side is up. Try it both ways carefully – it should not take much force to slide it in the proper way.
After you double-check all connections, it is time to power it up!
If everything is in order, Windows should immediately recognize your assembled components as an external monitor. Next you need to run a few tests to make sure your LVDS cable isn’t noisy. A well-made LVDS cable has a few specific pairs twisted together to reduce noise. However most cables you will find on EBay are not properly twisted which can lead to visual artifacts. To make sure your cable is good, you should load several different images on your LCD screen, the more images you try, the better because sometimes the artifacts only show when a specific color is displayed.
If you see any artifacts, there is an easy way to mitigate most or all noise. All you need is some tape and someone to help you. First, gently twist the cable around itself but be careful to not put too much tension and then while you hold the twisted cable, ask someone to tape it so it will remain twisted after you let go of it. This trick worked for me every time!
