Smart Led Softwares

The level shifter is actually not a stand-alone ic. But it is an integral part of the Scan Driver circuit, to provide various kinds of Gate Lcd panel driver pulses. Scan driver (Gate driver) itself functions as an on-off control switch to turn on and off the LCD pixels from the sides of the screen. While the dark light of each pixel is controlled from the data drivers that are on the top or bottom of the screen.

What is the Level shift function

This can happen to LG using the GIP panel (Gate In Panel). Which is marked by the voltage VGH_ODD and VGH_EVEN from Tcon that enter the panel (picture above). If the voltage is measured at the two TPs, they will continue to change periodically ... Sometimes positive at VGH voltage / sometimes negative at VGL voltage. VGH_Even and VGH_Odd the voltage is always opposite. This means that if VGH_even is positive, then VGH_Odd will be negative. The same symptoms can also be found on AUO panel models. Where there is also found a TP whose voltage is always positive and negative. Read: AUO panel images are sometimes good, sometimes double or blurred This is not a damage to T.con, but a glass panel damage similar to damage to a Samsung image panel vibrates. The solution to the problem above is: The first step. Observe the picture ........ while measuring the voltage VGH_odd (or it could be VGH_Even) Observe carefully the voltage when the image position is good, what is the VGH_odd voltage. For example a good picture when VGH_Odd positive voltage. Second step. Cut the VGH_Odd and VGH_Even paths that enter the panel from the source. This voltage comes from an IC called LEVEL SHIFTER. Third step. After the path is cut off. Because the picture is good when the position of the voltage VGH_Odd is positive. Then the jumper directly VGH_Odd to VGH And the reverse is the VGH-Even jumper to VGL. Note: If the picture is good when VGH_Odd is negative. Then VGH_Odd is jumped to VGL

Images change periodically. Sometimes good pictures are defective ... ... alternating periodically. Defects can have various symptoms: maybe vibrate, maybe lines, maybe double etc.

How to Cut & Jumper on the LG GIP panel

Use the ohm meter from the Lc1 and Lc2 test points towards the ic Level Shifter to locate the Lc1 and Lc2 pin-output legs. Third step. After the Lc1 and Lc2 lines from the Level Shifter ic are cut off. Because the picture is good when the Lc1 voltage position is negative. Then the Lc1 jumper enters the glass panel COF with a voltage of Vgl. And the opposite is the Lc2 jumper with Vgh voltage. To be safe we ​​usually do not with direct jumpers, but we put R 2.2k each. The Level Shifter IC used by the AUO panel T.con AUO uses several different type of Level Shifter ic, as well as the number of scan driver pulse outputs Some use a box-shaped IC with the number of legs: 24inch (5 x 4) small panel type i7238, ATT1908 with Hc1 to Hc4 scan drivers. 32 inch (8 x 4) panel type AUO S302.1V with Hc1 scan driver up to Hc6. 50 inch (10 x 4) panel type AUO M106-11 with Hc1 to Hc8 scan drivers.

The picture changes periodically with the AUO panel problem. Sometimes good pictures are defective ... ... alternating periodically. Defects can have various symptoms: maybe vibrate, maybe lines, maybe double etc. The same thing is often found on LG panels that use the GIP panel (Gate In Panel). Unlike the LG panel which uses the terms Vgh_odd and Vgh_even, the AUO panel uses the terms Lc1 and Lc2. Lc1 and Lc2 voltages always change periodically, sometimes positive at Vgh voltage and sometimes negatively at Vgl voltage. Lc1 and Lc2 voltages are always opposite, meaning that if Lc1 is positive then Lc2 is negative, and vice versa. The Lc2 and Lc2 voltages from the IC Level Shifter branch off in two directions. One to the left and one to the right, each entering the COF pane of glass. The solution to the problem above is : The first step. Observe the picture …… .. while the voltage measured Lc1. Observe carefully the voltage when the image position is good, what is the voltage Lc1 For example a good picture at negative voltage Lc1. Second step. Cut the Lc1 and Lc2 paths directly from the source, i.e. the outputs from the ic Level Shifter Usually the L1, Lc2 output lines from the Level Shifter ic are mounted like R Jumpers. So in this case we do not need to cut lane, but enough to remove the R jumper.

Method cut & jumper AUO Level Shifter panel

Do all the same T.con work. In principle, all types of T.con are "almost the same", because they all have the same purpose as explained in their main function. The difference is caused by each panel manufacturer competing to make their own designs. The inventions in the design of how T.con work are usually patented so they are not imitated by other brand manufacturers. Everything is developed and aims to obtain better image quality, lower production costs, so that the price of Lcd aircraft from year to year can be pressed continuously. The glass panel component is by far the most expensive component. Or about 75% the price of a television plane. The striking difference is that it is a Gate-driver circuit design, so that in general we know it until now several types, such as: Samsung panel technology (panels with type LTAxx, LTFxx, LTYxx) that we know uses pulses2 for Gate-drivers with the names CKV1, CKVB1, CKV2, CKVB2, STV. Gate-driver circuit is embedded in glass panels better known as ASG (Amorphous Silicon Gate) technology AUO panel technology (panel with type Txx) that we know using Gate2 driver pulses with the names Hc1, Hc2, ... .. LC1, Lc2, STV LG panel technology (panel with LCxx type) which is actually almost similar to AUO which is better known by the technology where the Gate-driver is embedded in a glass panel known as GIP (Gate In Panel) technology. Here the Gate-driver pulse is named Clk1, Clk2, .... and Vgh-odd, Vgh-even, VST. BOE panel technology (panel with HVxx type), SHARP (panel with LKxx type), ChungHwa (panel with CLAAxx type), ChiMei (panel with Vxx type), CSOT (panel with MTxx type, STxx) are those that use "ear" which appears outside the panel as a Gater-driver. The number of ears can vary, it can be 2.3 or 4. This is certainly different from the technology mentioned above before, where Gate-drivers are all embedded in the glass panel.