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Monitor Backlight/Inverter Problem

Last response: in Computer Peripherals
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August 13, 2012 8:19:10 PM

Hello all,

I've been having issues with my Westinghouse M2401 24" monitor taking some time to turn on. You could hear it "charging" up and then flicking off, and eventually after a few times of flicking off, it would come on and stay lit until the monitor was turned off or went into hibernate and then needed to be turned on again. As time went on, eventually the monitor would try to turn on, and for a split second you could see the backlight kick on, then immediately off. Upon shining a light into the monitor, you can see the image on the LCD screen - but no backlight.

I first suspected the caps, so I took the monitor apart and found two bulging caps (one exploded). I ordered the same exact brand/voltage/farad rating caps and replaced them and the monitor now turns on much quicker, but still the same issue with the backlight coming on for a split second, then off (the image still apears on the screen, but no backlight).

From what I can tell, since the backlight comes on for a split second - it shouldn't be that, correct? If the backlight were bad it wouldn't light up at all. From what I've read, most sources are indicating its the inverter board thats the problem.

MONITOR: Westinghouse M2401
PANEL: Samsung LTM240CT04
INVERTER: ???
BACKLIGHT: ???

I've included a album of pictures http://imgur.com/a/PkU2o showing the panel and seperate boards. There are three separate boards, am I correct in saying that the board the VGA/DVI and power connector connect into is the inverter board? Or is it the long board by the backlight?

I do possess a multimeter rated up to 1000V I can use for testing.

Here is the spec sheet http://www.displayalliance.com/storage/1-spec-sheets/LT... which looks like it contains significant information. Hopefully somebody can help me out here??
a c 106 C Monitor
August 13, 2012 8:40:00 PM

The inverter board is usually at the bottom of the screen, in this monitor it looks to be the one in the 3rd picture from the bottom.
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August 13, 2012 9:46:49 PM

Thats what I thought as well, but looking at page 15 and 17 of the specification PDF - it seems like the inverter board is the fourth picture down in the album linked (also shown in picture #1). The inverter is the board that converts low voltage from the power supply to high voltage for the backlights right? The color/number of wires out of page 15 and 17 for the inverter board match the color/number of wires of the mentioned board. The spec sheet shows this board outputting 900V to the four backlights so I'm thinking this has to be it? Can anybody confirm my thought process there?

I guess the easy way to check if its the board or the backlights would be to get the multimeter on the inverter output and see if I read anything near 900V, but 900V makes me a little hesitant to try it. I shouldn't have to worry about arc at that voltage though and my multimeter is rated to 1000V. The output from the inverter should be AC correct?

This board does have one cap on it but it doesn't seem bulged or leaking - perhaps I should replace it as well just in case.

EDIT: Multimeter is rated to 1000V and the polarities were far enough apart where I wasn't worried about arcing or crossing the leads so I went ahead and hit the positive and negative coming out of the board and got zilch. This was after the backlight had already tried to come on and went off, but my LED indication light is solid green. Back to square one? Inverter or power supply problem?
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a c 106 C Monitor
August 14, 2012 1:52:51 PM

That other part looked like the inverter also, I went with my pick because the narrow thin one looked more like the other inverters I have seen, but those were for smaller sized screens.

You can get this monitor for cheap for what it is also http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Westinghouse is not a very good quality monitor, that name is not the real westinghouse just like Polaroid and several other brands. The name was sold to be used by anyone in China that wants to make a product.
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August 15, 2012 4:08:58 AM

hang-the-9 said:
That other part looked like the inverter also, I went with my pick because the narrow thin one looked more like the other inverters I have seen, but those were for smaller sized screens.

You can get this monitor for cheap for what it is also http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Westinghouse is not a very good quality monitor, that name is not the real westinghouse just like Polaroid and several other brands. The name was sold to be used by anyone in China that wants to make a product.



Wow, thats a great deal on a 1920x1200. I've been holding off buying one and trying to fix this one because most 16:10 aspect ratios are terribly expensive. My main concern is the 8ms for gaming. Noticeable?

EDIT: Wanted to mention I bought this Westinghouse only because I knew it had a Samsung panel in it, hoping it would be better quality. I knew Westinghouse was next to crap for display quality when I bought it.

I'd also like to mention that I'm more than likely buying another monitor regardless, but would like to keep attempting to try to fix this 24" so I can dual monitor. I've limited it down to the inverter board - but cannot find where to buy ANY online despite having the model # and everything from the PDF spec.

Has anyone had any luck with these "universal" inverter boards? I would have to find the right voltage/amperage/etc - http://www.ebay.com/itm/UNIVERSAL-INVERTER-10V-30V-4-La...
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a c 106 C Monitor
August 15, 2012 1:36:20 PM

I have about a 10ms IPS screen and several people in the family play games on it with no complaints. That price is super for a new Dell UltraSharp, they have always gotten top reviews.

Never tried a universal board myself.
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