Master Electronics Repair !

Welcome to Master Electronics Repair! website.Here you will find:Service Modes, Circuit Diagrams,Service manuals, Firmware Update procedure, Disassemble procedure, Universal remote control setup codes, Troubleshooting, Diagnosing, Measuring, and more.... of many of LCD/LED TV/Displays,others various electronic apparates,trough many technical notes and tips/tricks to help repairing/fixing Troubles/ faults,for electrical technicians.This site helps you to save the Earth from electronic waste!

Richtige Fernseher haben Röhren!

Richtige Fernseher haben Röhren!

In Brief: On this site you will find pictures and technical information about Service Modes, Circuit Diagrams, Firmware Update procedure, Disassemble procedure, Universal remote control set-up codes, Troubleshooting and more....

If you go into the profession, you will obtain or have access to a variety of tech tips databases HERE IT IS Master Electronics Repair !.

These are an excellent investment where the saying: 'time-is-money' rules. However, to learn, you need to develop a general troubleshooting approach - a logical, methodical, method of narrowing down the problem. A tech tip database might suggest: 'Replace C536' for a particular symptom. This is good advice for a specific problem on one model. However, what you really want to understand is why C536 was the cause and how to pinpoint the culprit in general even if you don't have a service manual or schematic and your tech tip database doesn't have an entry for your sick TV or VCR.

While schematics are nice, you won't always have them or be able to justify the purchase for a one-of repair. Therefore, in many cases, some reverse engineering will be necessary. The time will be well spent since even if you don't see another instance of the same model in your entire lifetime, you will have learned something in the process that can be applied to other equipment problems.
As always, when you get stuck, checking out a tech-tips database may quickly identify your problem and solution.In that case, you can greatly simplify your troubleshooting or at least confirm a diagnosis before ordering parts.

Happy repairing!

Today, the West is headed for the abyss. For the ultimate fate of our disposable society is for that society itself to be disposed of. And this will happen sooner, rather than later.

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Note that if you don't find what you searched for, try it after a period of time; the site is a never ending job !

..............The bitterness of poor quality is remembered long after the sweetness of todays funny gadgets low price has faded from memory........ . . . . . .....
Don't forget the past, the end of the world is upon us! Pretty soon it will all turn to dust!

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All posts are presented here for informative, historical and educative purposes as applicable within fair use. NOTHING HERE IS FOR SALE !

Wednesday 6 March 2019

LENOVO L2021 WIDE LCD MONITOR SERVICE MODE - SOFTWARE UPDATE - DDC WRITING - POWER SUPPLY CIRCUIT - POWER BOARD715G4174-2 - LD7552BPS - BACK LIGHT INVERTER CIRCUIT – LCD MONITOR REPAIR AND SERVICE – MANUAL SERVICE

LENOVO L2021 Wide LCD Monitor Service mode - Software update - DDC writing - Power supply circuit - Power Board715G4174-2 - LD7552BPS - Back light Inverter circuit – LCD monitor repair and service – Manual service

Category: LCD Monitor Repair and Service

Contents of this article

How to access service mode
Software update procedure
Power supply circuit diagram
Back light inverter circuit

LENOVO L2021

Maintenance

Maintainability Requirement
1. Voltmeter. & digital multimeter
2. Oscilloscope.
3. Pattern Generator.
4. DDC Tool with Compatible Computer.
5. Alignment Tool.
6. LCD Color Analyzer.
7. Service Manual.
8. User Manual.
9. repair tools etc

Disassembly SOP
Precaution
Please read the precautions as follows to prevent any damages to the LCD Monitor
Make sure all power connection is removed. Be sure that the LCD Monitor is in power off status.

1.Prepare soft cloth and sponge as working platform to place LCD monitor horizontally.

2. Hold LCD by the side carefully and DON’T touch or press panel directly.

3. appropriate tools
select the appropriate tools for disassembly and re-assembly.

Phillips screwdriver
spacer screwdriver
C/D Disassembly Tool
Gloves or soft cloth

Software update step
After replacing the Main board and the Panel, Check if white-balance is within the specs ,then re-writing DDC is necessary.
Software information

U401	056G1125191	IC RTD2122L-LF LQFP-48
SMTCR-U401	100GLRSA006B11	L2021W_SEC_LTM200KT03_M20_ RTD2545LH_100729_v0.01_Eng.H00
U501	056G 562201	IC RTD2545LH-GR QFN-48
	CBPCARJG1J1	G3327-1-X-X-2-090407 FOR L2021WA

1. Connect USB cable to the PC USB port and the ISP tool,（ 715GT089-B）；
2. Will be the Monitor VGA cable to connect ISP tool ；
3. ISP tool card connection as shown below

Step2： Installing driver software
1.To install the USB driver software, mstar ISP Driver3-DB07-6-XP-driver

Step3： Run software “RTD Tool V1.7 version”

1.selected ISP,-àRTD2122 ,as shown in, Press the icon to select,Note save HDCP key:

2.selcted “Page Select”

3.Click “64K”,selcted software files

In this way, Automatic Identification space size,Next ,selected “Externd True Size”

4.Click Program icon ,Programming started,After Programming, Appear PASS.

Writing DDC program step
1. Prepared the PC with Windows XP system, DDC recording device (12V)for figure below
2. Connect the DDC recording device and the PC through PC parallel port
3. setup “Port95nt” driver program to PC ,
4. select relevant program and run it, below figure will appear
5, Press “LoadFile”, select EDID -model of product, and select input port;
6. key in SN,and other informatiom, key-press “Pragram” button;

SERVICE MODE

Factory mode adjustment
After replacing the Main board and the Panel, Check for enter the Factory mode ,then re-writing DDC is necessary.
Press MENU button and hold,reinsert the Power cord , then ,press MENU , the monitor will may enter Factory OSD Menu. Then Press . Factory OSD Menu will appear in the screen.

In normal user mode, open the menu to restore factory default values

POWER SUPPLY CIRCUIT DIAGRAM

Power Board715G4174-2

CLICK ON THE IMAGES TO ZOOM IN