LCD Monitor Driver Board, Inverter Maintenance Tutorial

LCD monitor circuit board components big density, is not easy to identify, patch component model accessories difficult to buy, and instead board easy to get, and the price is suitable, so in many cases are is by changing the corresponding to the maintenance function circuit board, the so-called board level maintenance.

Board level maintenance main including drive board substitution, the replacement of the inverter and the power of the replacement of the board. Some type of power inverter board and is doing in together, already can respectively substitution, also can use the power supply voltage one board the whole generations change. Due to a power supply part circuit is simple, easy maintenance, little board level maintenance, so this paper only drives inverter board and the substitution method and the matters needing attention in this paper.

A driver, the replacement of the board

Driver board is to point to LCD monitor the whole small signal processing circuit boards, including VGA (DVI) signal input, MCU control system, two times the power supply voltage stabilizing, liquid crystal screen interface circuit, etc. Generally speaking, a driver board switch on the power, with good screen OSD line and according to JianBan, then grafted in inverter, is a complete LCD monitor circuit. Burn through different programs, the driver board can adapt to all kinds of LCD screen.

Optional driven plate mainly to see whether the driver interface board and need long display tally. Through the interface to the work can be explained, shows how the selected drive board.

1. The screen line interface

Screen line interface must LCD screen and cooperate. LCD monitor the use of the main screen interface and TTL LVDS interface two kinds, TTL interface mainly focus on the following 15 inch LCD screen. LVDS interface is covering 13.3 inches above 90% of the LCD screen. Two interface drive mode, screen line shapes different, is not compatible. Judge LCD screen is what kind of interface, mainly through the access to this type of liquid crystal screen technology handbook. Experienced maintenance member can also shape or through the interface of liquid crystal screen type direct judgment. For example, M150X3-L01 LVDS interface is the LCD panel, and M150X3-T03 is by mouth the LCD panel TTL, between the two in the suffix a L model and a T. So, if you can't clear judgment of liquid crystal screen type, must put on the LCD panel and model about all the letters and Numbers tell driven plate distributor.

LVDS interface pin number in 30 the following, cable, the name is DO a, DO +, D1 a, D1 +, D2 a, D2 +, CK ~, CK +, D3-D3 +, etc. If the six screen, there is no D3-a group of signal the D3 + c common are 20 feet and 30 feet of interface, the early 10 inches to 12 inch screen also had 14 feet of the interface.
TTL interface with LCD screen and * * laptop LCD displays of the assembled into the majority, the interface pin general in 41 needle above, most to the next board with special turn and driving plate is linked together, so the cost of changing plate is higher.

Maintenance general board has 3.3 V and 5 V voltage jump line so that the power to choose, be careful not to make a mistake. Because RSDS interface, * * S interface dosage is very few, it shall not be introduced in this paper.

2. The video card signal input interface

17 inches below the display, mostly only VGA signal input interface, because the VGA interface is driven plate basic configuration, so low can not be considered. 17 inches above the display, a lot of the VGA + DVI double interface way, if only with single VGA driver interface board, the user does not accept, be about to choose VGA and DVI double interface drive board, the cost will also increases.

3. According to JianBan interface

According to JianBan OSD of LCD with 4 to 7 keys to 5 keys are in the majority. How many of the key support the decision by the drive program, and driving plate buttons interface in how much needle, not five buttons including POWER, AUTO, DOWN and UP, MENU, six keys will increase the ENTER key. When maintenance can be used the method of flexible. For instance, some LCD monitor is 6 key, but only 5 key program, it can not ENTER key empty; Be like again, a LCD monitor is four key, and only 5 key program, can abandon AUTO needle inserted and not pick up, so that does not affect use; Part of LCD JianBan is through the flat in soft row with driver board connect the line, can't drive board with matching, right now, can give up flat line line, one with the thin wire connection, installation empty ask special small, can use wire enameled wire connection.
In addition, to pay attention, maintenance general board can make is the key of the way short sub, and many of the PinPaiJi according to JianBan is the resistance points the way pressure, therefore, to the original machine according to the relevant JianBan resistance take out, through the jumper into resistance on short way to pick up. For the film and not to short of buttons by the way, or a key of the shuttle, if the original keys bad changes, we have to buy another according to JianBan and then find suitable location installed.

4. Inverter interface

The sold maintenance generic driver interface for high pressure plate more + 1 2 V double needle, GND double needle, BLON and wild. Most ADJ function is virtual didn't of, that is, the foot voltage is fixed, not with the brightness to adjust and change, brightness is completely through the software in the control chip internal simulation of the AD. In fact to 3 line transfer to inverter.

At the same time in wiring simple, also brought some of the inverter and not compatible, and appear boot after a bright put out, or can't adjust brightness anyway also go up. The former solution is, the original inverter control side brightness directly grounded, the latter need through a proper resistance even the + 5 V and the original inverter brightness to adjust end. The so-called appropriate, because its resistance to change with the inverter parameter adjusted flexibly, not the same and the resistance for more than 2.2 kQ or so.

5. Power source

Maintenance generic driver interface board for 12 V power input. If is the external power adapter, add to pick up a universal plug it; If the power is built, it will have to through a wire welding to the original mechanical and electrical source on the corresponding solder joints.

Note, wire shall not be too thin. Part of the PinPaiJi secondary voltage stabilizing the main source for 13 V, can be directly connected, do not affect use. Some built-in power the 13 V (or 12 V), 5 V party type, can give up 5 V need not, because of the liquid crystal display 5 V power load not heavy, will not affect the normal work circuit. Some PinPaiJi only output a group of + 1 8 V power supply (the part of the aircraft fly miura), and so to the original machine on voltage stability of the quarter change, make its output + 1 2 V voltage can only after. If rushed through, burn down driver board.

Second, the replacement of the inverter

Liquid crystal displays of the inverter is the most commonly used one lamp ~ 4 lights, and have a big and small mouth of the points. The number of light depends on how much liquid crystal screen, such as 4 lamp LCD screen (1 7 inches above the display) will match 4 lamp inverter, 1 lamp LCD screen (14 inches below the display) will match 1 lamp inverter.

1. The big and small mouth

Big and small mouth is refers to the inverter and tube connection interface width, difference and because lamp quantity and different.

1 lamp inverter and basic it is small mouth, even if there is big, you only need to put the tube connection directly welded in corresponding position, can, do not affect use.

2 lamp inverter big and small mouth the distinction is not big, but high pressure interface width different just, mutual substitution is very convenient.

4 inverter big and small mouth lamp of a bigger difference. Big of an interface to pick up two tubes, that there was a connection is common. With big inverter substitution small mouth OEM L305-S5944 inverter , just need to take a group of two tubes original lines (DiYaXian) parallel together take public line and the remaining two line separate connection can; With small mouth inverter substitution big inverter, because a group of two different tubes loop (only a few inverter is the same), it can not be simply two low voltage interface in parallel, need to view LCD screen tubes wiring, will DiYaXian separate, then connect the corresponding, otherwise it may cause failure.

2. The line interface either 1 lamp inverter, or 4 lamp inverter, is inseparable from the interface. Through the connecting cables and drive very connected, accept the MCU control. For the GND pin, VCC, ADIJ and BLON. Namely, power supply, brightness to adjust and high voltage switch, different drive indicated by a board of letters makes a difference. The main difference is the control interface is how many of the pins and the form of wire. The same four pin some leads 1 a needle inserted, of which more than have put the needle in parallel. Especially GND pin and inserted into VCC needle as current is bigger, use more more in the form of needle in parallel. Using a multimeter to measure resistance or watch circuit board copper foil can difference.

Control interface using wire form of different, is mainly refers to ordinary wire and flat stream line line. The former even if the interface is different, need according to meet H function just one docking, easy to solve. The latter if is flat line line damage it can be difficult to find substitute, its maintenance method is: welding the row line off the interface to thin wire enameled wire connection, etc.

3. The number of different lamp inverter substitution some readers will ask, not to say a few lamp LCD screen with a few of the OEM L455D-S5976 inverter to the substitution? And how the number of different light can also substitution inverter? In the maintenance or DIY, often need not with the number of lights on the substitution between inverter. Substitution principle is, the less light can be more than the lamp replacement, if use many of the substitution of the lamp light less, is to change the circuit, more trouble.

Under what circumstances would involve different lamp inverter of substitution between number?

A volume is not allowed. For example a 2 of light in hand display, the original machine inverter volume is very small, 2 lamp inverter contain, can use 1 lamp inverter substitution (1 lamp inverter smaller), already: can use two 1 lamp of parallel substitution, light at the two lights tube, can also be idle a lamp, with only one 1 lamp light up one high linking piece tubes. Theoretically, such substitution for tube haven't fully lit and the brightness will reduce about 25%, brightness will not even, but actually very ugly out, the visual effect the impact is not big, especially to the office or word processing monitor. The author use the display is deliberately only light one tube, in order to achieve energy saving and reduce the purpose of the dazzling light. In general, the light of the inverter can substitution 1 2 lamp, 2 of 4 inverter can substitution lamp light.

2 it is no accessories. LCD monitor is four lights, and have no 4 lamp inverter, where you can recommend guest door inverter with 2 lamp to brighten LCD screen.

4. The monomer inverter of many display USES is the replacement of the power supply voltage one board, if only high pressure partly damaged whether to replace the entire circuit board? The answer is no. Change the whole board while convenient but not economic, volume and suitable one plate is not easy to get. The right way is: first to circuit analysis, the high pressure part of the components down. And then in the position to make the fixed the new inverter, completes the insulation protection.

From the driver plate to one board connection method: find ADJ and BLON (the two line many can parallel use), and received inverter control interface into the corresponding needle, again in a power board to find and + 12 V, inverter control to meet H in the corresponding needle, has been accomplished.