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  • genesgiel_20 Nov 20, 2008



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Samsung 2233RZ going black after 1-2sec

First if you can, try the monitor with other PC first to make sure it is not the PC problem.

If it behaves in the same fashion, then most probably has dying power supply due to bad DC filter caps, just see the top side of the caps to ensure it has not bulged up distorted.See the images bellow
12_24_2012_5_33_15_pm.jpg OR


Then there is the logic board. Plug the monitor in but do not activate the power switch so the backlight inverter circuits will be off. Check the 5vdc and the 12~24vdc to make sure they are OK. They should be tested with the load, you can use 6V 1A (6watts) lamp for the 5vdc, and car lamps such as 1157 (12v 8watts lo/26watts high) turn signal brake lamp using high filament connection for testing the 12~18vdc (or use two 1157 in series for 19~24vdc) for the backlight inverter circuits.
If the power supplies are working, the output voltages should be steady at the rated voltages. The power supply will go into shut down if it detects too much current draw due to false in the power supply or short circuits in the backlight inverter or in the logic board.

The backlight inverter circuits:
It takes the 12~24vdc and converts it to high frequency AC to drive the inverter transformers CCFL (Cold Cathode Fluorescent Lamp) assemblies. The transformers will drive the CCFL by applying the start up voltage (around 1500~2000v), when the CCFL start conducting, the voltage will drop down to about 500~800v.
The inverter has detection circuits to detect open circuit if the lamp is not attached or does not fire up after the start up voltage is applied, it will go into shut down. It will also shut down if the lamps draw too much current due to ages (when lamp gets old it will draw more current).
The inverter gets two signals from the logic board, one is the backlight ON/OFF signal, the other one is the Dimming signal for the lamps.
Common problems:
Bad filter caps, resonant caps (in the inverter output circuits), blown transistors/IC, shorted or open transformer winding.

If you are confident with your skill then go ahead else go to an authorized outlet for repairing
Do write back if you face any difficulty while working on the monitor

Dec 22, 2012 | Computer Monitors

2 Answers

A few months ago my LG Flatron L1900R monitor started flickering when I boot up my computer. It has become worse, to the point where it now flickers constantly.

From the information desribed, this means that your CRT monitor is going dead. Unfortuntly, there is no way to stop the flickering unless the monitor was replaced. I hope this has helped

Jul 05, 2011 | LG 700M 17" CRT Monitor

1 Answer

Monitor flickers with lines across screen

screen is going bad which is why its flickering and has the lines across the screen. Theres a board behind the lcd and when that doesn't process the voltage properly it can cause the screen to flicker. White lines across the screen means the screen is going bad. At this point unless your monitor is under warranty, go ahead and replace it.

May 28, 2011 | Norcent Technologies LM-965WA Monitor

1 Answer

Same issue. 5VDC & 15VDC OK even when CCFL's go off. New 1,000uf/16VDC cap. Just prior to going out screen starts to flicker slightly. Can't see any bad solder joints on the power board. Any hints?

The 1000uf/16vdc caps are for the 5vdc logic, there should be at least tow caps rated at 25vdc for the 15vdc inverter circuits. Try using 1157 12v car lamp attache to the 15vdc, the power switch will have to be off (the 5vdc and 15vdc are always on) so the inverter circuits will not be drawing the current from the 15vdc power supply, the 15vdc should be at 15vdc +/-1~2v with the lamp load. If it is steady, then you still have problem in the inverter circuits which can be the lamp assemblies, inverter transformers, Transistors/IC. I use test lamps set up to narrow down the problem to find out if it ia the lamps or the inverter circuits.
Failed TV and Monitors:

Service manual:

Sep 10, 2010 | Sony SDM-HS74P/S 17" LCD Monitor

1 Answer

I have a L1930b with a bad panel. I have a panel that will fit this monitor but it is an LM190E03-B4, which takes 5V input, whereas the original panel takes 12V input. The power inverter is a Lien Chang...

You can use the 5vdc from the monitor power supply
Service manual:

I look at the diagram page 31, pin 1~3 is the VCC for the panel with notes for 12/5vdc, it can be connected to the 12 or 5vdc, so it must have a jumper on the board somewhere that will let you choose 12 or 5vdc for the panel, the main thing is that the rest of the panel pins match the original panel, please verify that first.

Failed TV and Monitors:
Capacitors kit: he can make you a set of caps for you.

Sep 08, 2010 | LG L1930B 19" LCD Monitor

1 Answer

When logging on, my screen goes white (totally) for a short time (about 30 seconds). and then, i can see my homepage in pieces flickering until it comes in completely. i don't know if this is a computer...

It means taht you may have loose cable connection between the logic board and the LCD panel T-CON board, that will be the first place to look, it can also be that it is losing the 5vdc feeding the T-CON board. Please see T-CON album to see what T-CON board looks like.<br /> <span style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'; mso-bidi-font-size: 12.0pt"><a href=""></a></span><br /> <span style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'; mso-bidi-font-size: 12.0pt"> </span><br /> <span style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'"><a href=""></a></span><br />

Aug 27, 2010 | Envision Computer Monitors

1 Answer

Dell e228wfp LCD with no power.

You need to check the voltages first, on the electrolytic caps in thepower supply section with voltage rating from 10~16vdc should have 5vdc on the two legs of the cap, this 5vdc is used for the logic board. The other caps with voltage rating of 25~35vdc should have about 12~18vdc on it's two legs. That is the starting point, these DC voltages are in the secondary side of the power supply, be careful on the HOTside of the power supply, it has high voltage about 160vdc and 120vac which can kill you, so be careful. If you can post pictures, it will help. See example of my pictures here:

Jan 24, 2010 | Dell E228WFP LCD Monitor

1 Answer

I have a 26" monitor. Input is 24vdc 5amp. The picture keeps on flickering. Is this a power issue?

maybe yes maybe not... try your monitor to another system unit... maybe the video card.. after that if no improvement.. call your dealer

Nov 28, 2009 | Computer Monitors

1 Answer

The task bar along the bottom of the screen, I can't see it

Adjust controls on the monitor. There a double box that lays on top of the other. Adjust that option... You may also want to adjust the setting that shows a box with arrows pointing up and down. adjust it as well.. Experiment on the settings. You'll get it right.

Mar 14, 2009 | Hitachi SuperScan Elite 802 21" CRT...

1 Answer

My monitor comes on long enough to show the e then says no signal! Please help what could be causing this problem?

Two things to check , to do, to assertain the point of failure .

1. Disconnect the signal cable coming from the monitor to the computer tower.If the monitor goes out there can be a problem at the monitor.
2. Check buy attaching a different monitor.

If the different monitor also doesnot work , the problem could be your video card or motherboard.
If you posted on the forum, using a laptop , connect your monitor screen to the laptop and check by toggling the display from the laptop screen to the extrenal monitor .


Dec 09, 2008 | Computer Monitors

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