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Backlight inverter Sir what is a backlight inverter? because you said I need to replace it,what is it look like it is an IC

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  • neiljopia Oct 20, 2008

    thank you very much sir.Sir if i plug my CRT monitor compaq mv520 into AC outlet and I turn it ON the power led flashing orange to green color and vice versa and I turn it OFF back then I connect into The system Unit and I turn ON the Systen Unit as well as the monitor and I found out that the power led stop flashing but from green turn into orange which is stand By Mode.Sir My System Unit have no problem because I try it into other monitor it works fine So the problem is in my monitor.Sir it is posible that the problem is in the Power Supply of the monitor? Help me Find out sir,Thanks in advance!!!

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A backlight inverter is the power supply to power the lamp or lamps in an LCD display, so when you look through the LCD there is a souce of light behind it. Kind of like holding a peice of paper up to a light and looking through it, The light from behind shines through the paper or in your case the LCD display. You would have to open up the LCD case in order to find what is usually a long thin board, similar to the one below. This may need to be replaced or you may get lucking and just be able to replace the F1 (fuse) component and fix it. (or have a techical friend do it for you)

Posted on Oct 19, 2008

  • DICKHUX Oct 19, 2008


    Example Inverter Board

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I hv got LCD TV hv No picture but have very good sound. While power put on ,it flash & go. What to do? This is for BenQ LCD TV 2680.Back light inverter is avllable? in case needed.


Hello
As you thinks mey correct to an extent. If backlight inverter board has some kind of short with its components, the fault you describes here will occur to LCD TVs, irrespective of Brand and Model. Most of the backlight inverters for any models are available at open electronic spare part shops at your town. Just take the backlight inverter board out from your Tv. It will have a special number printed on it, and should be noted when buying a new one. Remember its connections when you take the boaed out from your set. If needy, mark the positions of connecting wires to that borad on a piece of paper, for reference.
Replace the backlight inverter first. It must solve the problem of your BenQ LCD Tv. OK.
gopakumarg43

Oct 07, 2011 | Computer Monitors

1 Answer

Benq fp222w monitor switches on but black screen no backlight what parts need replacing to fix pls


If there's no backlighting but you can see the image anyway, then your monitor might have a defective inverter. The inverter is responsible for providing power to the backlight, so if it is defective, the light won't work and it might need to be replaced.
An LCD inverter looks something like this:

denisgomes.jpg

You can easily find inverters for sale online, but be careful: you have to find the exact same inverter for your monitor, or it may not work.

Mar 02, 2011 | BenQ FP222W LCD Monitor

1 Answer

Monitor has gone dark. Have checked connections and cables. Also attempted a system reboot and power down. No luck


Do you have the power light lit (standby or on)? If that light is not on, then it is probably the power supply.

Otherwise it is the board that translates the signal to the screen, the backlight or the inverter. It's a backlight or backlight inverter issue. (The backlight itself usually fades or makes the on-screen image change to pink/red.) With a bad backlight, you'll usually see a very dim image if you look at the monitor from an inch from the screen. Block the room light from overwhelming this image (sometimes a carefully positioned flashlight will help you see something). If the inverter or video board is bad, you will see nothing. For an out-of-warranty monitor, open up the back of the monitor and remove the shielding. Look for any scorch marks or bulging or damaged capacitors. (Sometimes other parts will fail on this part but these can be spotted easily. Capacitors look like cylinders on a tripod.) The scorch mark and smoke may indicate a resistor or zener diode that had been used as a fuse and is now gone.

If you borrow (or have a) high-end multimeter (able to measure high frequencies - 50 kHz) or an oscilloscope, hold the multimeter probes a fraction of an inch apart about an inch above the inverter board and power up the monitor. If you see a 1 or an actual value, you have a good inverter. If you see a reading near 0, the board is bad or the multimeter can't resolve the frequency.

In either case, you can buy a replacement inverter for $50-150 and just do a simple swap. Disconnect all of the wires (connections are similar to molex and ribbon cables in a computer) and remove board (a few screws usually). Connect the cables to the new inverter. (If you google backlight inverter replacement, you'll find videos and text descriptions.) Note the part number on the board, including the Rev number, and order the exact one (shopjimmy.com or lcdparts.net are good starting points). Universal inverters do exist but can result in reversed controls (up to lower the brightness). Replacing individual parts on the board is cheaper but more prone to not tracking down all of the bad parts.

If the inverter is good, then it's probably backlights themselves (several in most larger monitors). These are sandwiched on the perimeter of the monitor (usually under some tape that holds the lamp, reflector and other parts together. You need to order by length and width and get ones for your monitor size. Separate the panel from the bezel. Remove the tape, and separate the reflector (make a note of how things are put together) then you have to Dremel (or use another rotary tool) to remove the plastic to get the backlight out. (They are often molded into the frame.) Then put in the new backlight and reassemble everything. (http://www.lcdparts.net/howto/default.aspx) but for an overview: http://www.inventgeek.com/Projects/BacklightFix/overview.aspx Then push the new backlights into place, reconnect the wires and close up the sandwich of tape and other parts around the screen. Then replace it in the bezel.

With a good spare backlight, you can test an inverter for condition (plug together and turn on the tv while the box is open). Similarly a good inverter can test the backlight.

I hope this helps.

Cindy Wells
(inverters usually fail before CFL backlights or the video board)

Oct 15, 2010 | Westinghouse 19" Widescreen Flat Panel LCD...

1 Answer

Trying ti fix a gate way fpd 1520 flat panal monitor i can see the image lightly but looks as if maby a bulb may be out any sugguestions on how to fix


LCD monitors use a fluorescent backlight system. A 15" probably needs just one. These are sandwiched on the perimeter of the monitor (usually under some tape that holds the lamp, reflector and other parts together. You need to order by length and width and get ones for your monitor size. Separate the panel from the bezel. Remove the tape, and separate the reflector (make a note of how things are put together) then you have to Dremel (or use another rotary tool) to remove the plastic to get the backlight out. (They are often molded into the frame.) Some backlights are sold without the wires. In that case, desolder the wires from the old backlight and solder them to the new one. Then put in the new backlight and reassemble everything. (http://www.lcdparts.net/howto/default.aspx) but for an overview: http://www.inventgeek.com/Projects/BacklightFix/overview.aspx Then push the new backlights into place, reconnect the wires and close up the sandwich of tape and other parts around the screen. Then replace it in the bezel.

Sometimes the inverter will fail but since you see the image that is likely not the case. However, you should consider testing the backlight with the inverter before installing it. (Unplug the old backlight (similar to a molex connector) (or desolder the wires from the old backlight and resolder them to the new one, depending on your backlight replacement), connect to the inverter and plug in. If it lights, you are good to go. Inverters can be tested with a high end multimeter (that can read frequency) or an oscilloscope. They cause an induced current which changes sign around the unit. Depending on the age of the inverter this can be 60 Hz or 50kHz. Hold the multimeter probes a fraction of an inch apart about an inch above the inverter. If a multimeter reads zero or near zero, the inverter is bad or the multimeter can't resolve the frequency. If you see a value or 1., then the inverter is good.)

I hope this helps.

Cindy Wells

Oct 07, 2010 | Gateway FPD1530 15" Flat Panel LCD Monitor

1 Answer

LCD model viewSonic vx2235wm, screen is dark, no visual display. However, blue light at the bottowm is on.


It's a backlight or backlight inverter issue. (The backlight itself usually fades or makes the on-screen image change to pink/red.) For an out-of-warranty monitor, open up the back of the monitor and remove the shielding. Look for any scorch marks or bulging or damaged capacitors. (Sometimes other parts will fail on this part but these can be spotted easily. Capacitors look like cylinders on a tripod.)

If you borrow (or have a) high-end multimeter (able to measure high frequencies - 50 kHz) or an oscilloscope, hold the multimeter probes a fraction of an inch apart about an inch above the board and power up the monitor. If you see a 1 or an actual value, you have a good inverter. If you see a reading near 0, the board is bad or the multimeter can't resolve the frequency.

In either case, you can buy a replacement inverter for $50-150 and just do a simple swap. Disconnect all of the wires (connections are similar to molex and ribbon cables in a computer) and remove board (a few screws usually). Connect the cables to the new inverter. (If you google backlight inverter replacement, you'll find videos and text descriptions.) Note the part number on the board, including the Rev number, and order the exact one (shopjimmy.com or lcdparts.net are good starting points). Universal inverters do exist but can result in reversed controls (up to lower the brightness). Replacing individual parts on the board is cheaper but more prone to not tracking down all of the bad parts.

If the inverter is good, then it's probably backlights themselves (several in most TVs). These are sandwiched on the perimeter of the monitor (usually under some tape that holds the lamp, reflector and other parts together. You need to order by length and width and get ones for your monitor size. Remove the tape, and separate the reflector (make a note of how things are put together) then you have to Dremel (or use another rotary tool) to remove the plastic to get the backlight out. (They are often molded into the frame.) Then put in the new backlight and reassemble everything. (http://www.lcdparts.net/howto/default.aspx) but for an overview: http://www.inventgeek.com/Projects/BacklightFix/overview.aspx

With a good spare backlight, you can test an inverter for condition (plug together and turn on the tv while the box is open). Similarly a good inverter can test the backlight. With a bad backlight, you'll usually see a very dim image if you look at the monitor from an inch from the screen. Block the room light from overwhelming this image (sometimes a carefully positioned flashlight will help you see something). If the inverter or video board is bad, you will see nothing

I hope this helps.

Cindy Wells

Jul 27, 2010 | ViewSonic VX2235wm LCD Monitor

1 Answer

Monitor on a emachine 250 computer comes on picture is very light faded in the background but no light


This is a typical symptom of a failing LCD screen inverter board or LCD screen backlight lamp. The backlight lamp failure symptoms are very similar to the inverter board failure symptoms. If you have to guess which one is causing the problem, try replacing the inverter board first. LCD screen inverter boards fail more often than the LCD screen backlight lamps.

Feb 16, 2010 | Acer Computer Monitors

2 Answers

Screen goes black but still can see the desktop??


Yes this is a back-light problem. The fault could be the inverter board which supplies high voltage to the CCFL lamp or it could be a faulty CCFL lamp, this lamp is a mini fluro tube.
For service, parts and DIY info check out LCD Parts - click on this link to their WEB site : -
www.lcdparts.net

Oct 12, 2009 | HP w2207 Monitor

1 Answer

Viewsonic VP2130B no Video


First off, on these monitors, usually the power board is also the inverter board. If its not on this model monitor, and you know that by opening it up and seeing the backlight cables connected to a different board, than that may be the problem, but it might not be.

Secondly, Why did you replace the power supply? Were you not getting anything? power light? anything at all?

If you were getting the power light, but no picture (black screen), something else was most likely the problem.

Your problem is probably the backlight. It sounds like its out. Does the backlight come on at all? If it doesn't and you can faintly see an image if you look closely or if you press the menu buttons and see a faint change in the screen, thats the problem. Normally I would say its either the power board OR the backlight, but you say you replaced the power board. You need to replace your backlight. You can do that a couple different ways:

1) Replace the whole LCD panel. This is a costly fix, so if you are adventurous and cheap like me I would advise against it.

2) Replace the backlight panel. You need a screen like yours that is broken, but has a good backlight. That way you get it cheap, because its broken and beyond taking everything apart and putting it back together again, its relatively simply.

3) Fix the backlight you have. There are tutorials on how to do this online, but its harder and more dangerous (mercury and toxins that can cause lots of damage). I wouldn't do this, but if you want to I would suggest doing it in a place with lots of ventilation.

There could possibly be a problem with your mainboard, especially if you see no image AT ALL and you don't see a backlight. If your power board/inverter and backlight are fine, you should see the backlight on, regardless of the condition of the mainboard. If you see the backlight, then the mainboard is the problem. If your power board failed, and the power light wasn't coming on before, its possible that the board fried your mainboard and potentially your backlight (although damaging your backlight is rather unlikely).

In any case, good luck to you!

Aug 13, 2009 | Computer Monitors

5 Answers

Suspect backlight inverter circuit--desktop appears completely for 1s and then loses backlight


"Latched Open Lamp Protection Pin 4", disconnect the transistor 7002 "D" Pin on BIT3105 Pin 4.

Oct 15, 2008 | IBM ThinkVision L170 17" LCD Monitor

1 Answer

HP Pavilion xt1170


- lcd backlight inside the lcd, or the inverter itself. Can you see a very faint image? - Very hard to tel if it's backlight or inverter, or both. Each part costs about $30. Backlight: www.lcdpart.com inverter: ebay Labour is not included, but will cost roughly $75. Still much cheaper to repair than to buy new parts from nanufacturer.

Aug 16, 2007 | HP Pav ZT1170 Monitor

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