A screen inverter is a small circuit board in a laptop computer that passes a power current from the body of the machine to the attached liquid crystal display (LCD) screen. It works by turning a direct electrical current from the motherboard into an alternating current. The alternating current then sparks what is known as a “backlight,” a complex series of signals that cause the images generated from the hard drive to appear on the screen. This instrument is also frequently known as a backlight inverter or an LCD inverter, among other names. It is critically important to proper laptop functioning, but it often one of the first things to fail in an aging machine. Repairs are sometimes possible but not always, and in any event they tend to require a bit of expertise.
The primary function of the inverter is to power the laptop LCD. To some degree, this means it is responsible for channeling energy from the mainframe to the screen so that the screen both illuminates and projects accurate images. Stand-alone “desktop” computers typically have monitors that are completely separate from their hard drives, and inverters in these settings don’t work the same way. Some translation is still required, but it is usually carried through an external cable connected to a video card. In a laptop, everything is build together, which means that these connections have to happen on the inside. The screen inverter performs this role.
How it Works
Inverter boards have become smaller and of better quality as laptop technology has improved, and their performance has gotten better and more reliable as a result. In most laptops this device looks like a thin strip with multiple switches and wires, and it’s usually located just below the LCD display, right in the hinge where the top folds onto the keyboard; people can access it by removing the plastic frame around the screen. It is typically connected on one end to the internal video line and on the other to the backlight. In addition to powering the screen, the inverter also creates a better screen resolution and can give users more control over their display options. Its primary job is to shuffle and interpret electrical currents.
Even though the device performs a seemingly simple task, when it fails the results are usually unworkable. Connection difficulties or wiring problems can mean that the screen will appear to be lit, but the light will be very dim and the images may be very difficult to see. This can make the computer difficult and frustrating to use, even if the memory and hard drive are in perfect functioning order. The LCD may display might also show only very faint images, or the laptop could appear to be powering up, but the screen remains dark.
Faulty circuits or bad conductor coils are two of the most common causes of inverter problems. It can sometimes be difficult in these cases to determine if the backlight has just burned out or if the inverter has gone bad. The symptoms of each are very similar and both can display a dark or briefly lighted screen with some or no images, but problems with the inverter are usually harder to fix. The backlight is often more like a light bulb that can simply be replaced; the inverter is a more complex piece of hardware that usually needs more extensive repair and reworking.
The easiest thing people can do when they suspect a bad screen inverter is to take their machine in to a repair shop, but this can get expensive. In most cases simple tweaks and reconnections can be done at home, provided people have some understanding of computer engineering.
There are multiple websites that detail the step-by-step process of accessing the board, examining the damage, and replacing it if necessary. Depending on the extent of the problem, simply buying a new inverter is often easier than trying to repair old problems. Many computer retailers sell this piece, and in most places it’s not very expensive. It’s often recommended that users check the warranty information on the computer before making any repairs or replacements, though; if the laptop still has a valid warranty, the manufacturer will usually take care of the repair at no cost.