LG DU-42PX12XC 42 in. Plasma HDTV - Page 2 - Answered Questions & Fixed issues

I have a PDP 50 V8 plasma TCL tv
Turns green and back to red
Ive been told its the power board

Hello; I am John at J D Electronics in Poland, Maine. I have an LG TV that was donated to me. It is a plasma model DU-42PX12X. It had 1 inch wide red and green vertical bar on the right and a blue and yellow on the left. These bars appeared intermittently. pressing on the control board would make the bars go away. I have read many blogs on this problem and they all say to replace the control board located under that huge A / V input board ( held in by 4 screws on the large aluminum frame). The original part is # 6871QCH038A The replacement ends with a C instead of an A Aprox 90 to 135 dollars. This board is used on many different LG and Zenith models and is a HIGH failure rate part. I like to know WHY parts/boards fail and I found out why this board fails. There is a large square IC in middle of the board aprx 1 1/8 inch square. This type of IC is called BGA or Ball Grid Array. The solder connections cannot be seen , since they are under the IC . This IC was not properly soldered at the factory and that is why hundreds of these sets failed. I used my hot air soldering station on it's highest setting to heat up this IC . The IC must be directly heated from the top and some heat on the bottom of the PC Board. Liquid flux should applied to the 4 side edges of the IC prior to heating. The bars are now gone! To get to this board, remove all perimeter screws and all middle screws of the back cover. The A V board will hinge back to expose the control board if you unplug the cables to the side inputs and the one to the button board. The set will still run face down on a table with something to prop up the bottom screen so you can watch the bars. If the set was run for a long time with the bars, there will be some darkening where the bars have " burned" the screen. This is perminent, but usually acceptable.

PS The black screen on one side is also related to a bad control board ! John

Hi:
First of all plasma's does not have an inverter board, those are used in LCD televisions only.
Yoru problem exsists on the Y-SUS board, this is the board left of the power supply, While standing behind the unit. The X-SUSTAIN board is on the right of the PS.
The most common failue in plasma televisions is the Y-SUS board, LG recommends when you replace the Y-sus replace the X-board as well.

Hi,

It sounds to me as you have a defect Y sustain or Z sustain board.

In general it is alway the same steps no matter the defect or even the make of the plasma.

You will need to remove the back cover to troubleshoot the plasma you will also need a digital multimeter. I will bet you have a defective power suplpy but you have to be sure you don't want to through your money away by shotgunning the set with boards.

First look for missing voltages at power on each connector (not just Vs and Ve look at all the voltages they are marked on label near the top of the panel) should be labeled with the proper voltage. If you have one start with the missing voltage and troubleshoot back, it is hard to say what the ultimate failed components would be but you should be able to track it to one board.

Rule 1 is troubleshooting is "start with your sense"

1. Look
2. Smell
3 Listen
4. Touch (not recommend)
these are the best give way, if it looks damaged it is if it smells burn it is, if it sounds wrong it is
1. Look - examine each component on the board look for something burnt, swollen or distorted, and look at the fuses.
2. Smell - Smell around the set see if you can smell a burning smell on any of the boards .
3. Listen- Listen for a buzz or an arc out of one of the board, it may be normal but unlikely if you have a defect.
4. Touch- Important because if the parts are getting hot then they are running, but if they stay cold they are not.

As for touch not the best idea on a power supply there is a high risk of shock, as some of the heat sink may not share ground and possible have a potential to earth ground between 5-500 volts.

You will need a DMM to check the diodes and the transistor non should read a short, if any do you will need to remove it and check it out of circuit if the component is not shorted but the short is still in circuit use the schematic to follow the leads to where else the short could be coming from and repeat.

I would have to say unless you are familiar with repairing with a schematic it can be complex. Your best bet is to do what best buy techs do.... Replace The Board. It is the fastest sure fire way to fix it.

Next remove the connector connecting to Y sustain and the Z sustain to the power supply and attempt to power the set on if the set powers with the connectors disconnected you have more than likely identified the issue as a failed sustain board now to go further.

THIS IS NOT YOUR SET BUT A GOOD EXAMPLE, I Do not have any picture of the interior of this model yet as it is not list on the hitachi service site yet, i made a request for it but yet to be posted.

Now reconnect the power connect to the y sustain and see if the set powers remember you will not get a picture but the lights on the front should stay light.

If the y main connected causes the set to act up remove the buffer boards and attempt again, if the y still causes the issue you have a failed y board. If disconnecting the buffer resolved the issue you have failed buffers and possible a failed panel, try replacing the buffers.

If the Y board connected the set still light normal disconnect the board and connect the z sustain and test the same as the y, if that causes the issue replace the z, If both board disconnected cause still no power replace power supply.

In my personal experience I would at least have the set professional examined most good shops charge less then $50 mine only charges $25 so it would be worth at least getting an estimate.

Let me know,if needed further assistance.

Hope i helped you.

Thanks for using ' Fixya ' and have a nice day!!

Hi, my name is John. Welcome to FixYa. Horzontal output IC. Thanks for choosing FixYa....John

There is a problem in CRT connector.need for replacement.out of focus problem.

Hello; I am John at J D Electronics in Poland, Maine. I have an LG TV that was donated to me. It is a plasma model DU-42PX12X. It had 1 inch wide red and green vertical bar on the right and a blue and yellow on the left. These bars appeared intermittently. pressing on the control board would make the bars go away. I have read many blogs on this problem and they all say to replace the control board located under that huge A / V input board ( held in by 4 screws on the large aluminum frame). The original part is # 6871QCH038A The replacement ends with a C instead of an A Aprox 90 to 135 dollars. This board is used on many different LG and Zenith models and is a HIGH failure rate part. I like to know WHY parts/boards fail and I found out why this board fails. There is a large square IC in middle of the board aprx 1 1/8 inch square. This type of IC is called BGA or Ball Grid Array. The solder connections cannot be seen , since they are under the IC . This IC was not properly soldered at the factory and that is why hundreds of these sets failed. I used my hot air soldering station on it's highest setting to heat up this IC . The IC must be directly heated from the top and some heat on the bottom of the PC Board. Liquid flux should applied to the 4 side edges of the IC prior to heating. The bars are now gone! To get to this board, remove all perimeter screws and all middle screws of the back cover. The A V board will hinge back to expose the control board if you unplug the cables to the side inputs and the one to the button board. The set will still run face down on a table with something to prop up the bottom screen so you can watch the bars. If the set was run for a long time with the bars, there will be some darkening where the bars have " burned" the screen. This is perminent, but usually acceptable.

either you need new cables for the back or some other electronic is to close

One of the buttons should have this function just try them all and see how you go. I have done this in the past.

Plug the dvd into the a/v input and see if it is clear. If it is then have the satellite co check the receiver.

Hi I have a LG RZ42px11 there are 6 vertical thick black lines running down the middle off the screen, when cold the TV seems OK but if it has been on for around 10mins or on standby the lines stay on screen.

Thanks.


Douglas.

Bad panel, call LG and see if they will replace the panel for you!
GOOD LUCK !

Hello,

Also, you might have gotten a power surge, or a power spike. This can also occur without a lightning storm. Sometimes through your power eletric provider.

A power surge, or transient voltage, is an increase in voltage significantly above the designated level in a flow of electricity. In normal household and office wiring in the United States, the standard voltage is 120 volts. If the voltage rises above 120 volts, there is a problem.

Of course though, Just trying to help.

Hello Raycalles hi, the popping sound is from the power supply section, this is caused by a blown up capacitor, this capacitor needs replacement. It is also advisable to check the cause of the blowup, check for shorted Inverter circuit that powers the backlight of your LCD TV, or any unusual things like loose screws and burnt parts. but first call your dealer for warranty. else inverter replacement is needed.

First of all, Plasma sets are not just plug and play. There are necessary voltages to check along with temperature readings of both those modules along with 3 others to determine which one might be defective. Let me what you have checked in order for me to help you!
Law of probability doesn't always come into play with plasma's.

I have the same problem the pic went out but have sound. where do i go to get the Yboard? do i need a special number off of it or something? I took it to repair shop and he said it would be like 500 dollarss to repair. but i see all kind of yboards on ebay for like 150?? how do I know what one to buy?

IHi Dicrewsmith, I am having the same problems with my flat screen Tv, it comes and goes too, though is seems to have made it's self at home as of late.
I can't help you , but was hoping that you may have found a solution to yours, as I am having trouble finding stuff here.

Hope you can help

Kris
post here or and to [email protected]

have you switch the broadcast to Air from Cable using the remote go to this and also let it scan for channels auto...hopefully this will do the trick

1 - Turn on TV and set input to port being used.
2 - Make sure PS3 is connected via correct cable.
3 - Power on PS3 via power button and HOLD IT for 5 seconds (release after the second beep). It should automatically configure your PS3 to the TV's native resolution for all settings.

Download the user's guide and go to page # 19 for more info on how to set up the TV to the proper input to receive all the channels.
Let me know if you need further assistance.