The small piece of circuit board, which is usually located underneath the plastic shell of your laptop’s screen inverter, is probably the cause of one of the most common problems related to screen failure and, more specifically, dimness, or darkness to the screen itself.
The main purpose of the inverter is basically to give power to the backlight. The way it works is simple, it takes power from the laptop itself by a small inverter lead that runs from the motherboard of the laptop, sometimes it is a direct lead on it’s own, other times this lead can be connected into the inverter through the LCD cable (the lead that runs from the motherboard to the back of the screen itself), giving the screen its visual display.
At one end of the inverter, usually the left end, the lead that gives it power is plugged into a small white socket and from the other end, usually the right side, the backlight lead from the screen is plugged into another white socket. The backlight is a very small, thin, long, very delicate light bulb that runs along the very bottom or sometimes the side of the screen.
The problems related to the inverter is dimness or darkness to the screen in most cases or flickering of the backlight. Sometimes it can stop the screen form working at all but not usually. A common fault with laptop screens is a dark or dim screen, generally it is assumed that it is the backlight that is at fault, sometimes this may be correct, however more often or not it is simply the inverter not working, or not giving the backlight the power it needs. The inverter is usually cheaper to replace than the backlight, as the backlight is very fragile and can be easily broken. On some occasions a repair of the inverter is possible, although usually labour charges on fixing the inverter can sometimes lead up to being more expensive than simply replacing it.
When it comes to purchasing an inverter most companies will require the part number which is usually printed on a bar code on the outside of the inverter but sometimes you may need to look carefully to find it. If your lucky then you may get away with just stating what your laptop make and model is, for example ‘I have an IBM Thinkpad T22 and I need an inverter’, we try our hardest to locate the inverter with just these details, however sometimes you will need to provide the part number; here is an example of a part number from the inverter for an IBM Thinkpad T22, (10L1402). This inverter is also compatible with the IBM T21, and T20 all three laptops as a whole are basically the same apart from the processor.