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Broken LCD monitor -- Fades out with green tint

Hello,

My LCD stopped working a while ago and I haven't been able to figure out what exactly failed on it. This is what it does:

1) I turn it on, it displays the signal/picture 2) Several seconds later it fades out with a green tint and then goes black. 3) I need to unplug it and leave it for about a minute before I can turn it on again.

Every time I turn it on in this state, it stays on for less and less time. I guessed that maybe the CCFL is dead, but don't they usually last a long time?

I have taken it apart and I can't see anything that is obviously burnt out/loose/ or just plain wrong.

Any clue as to what this might be? Or what I should replace?

Reply to
Antony
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On Fri, 02 Feb 2007 17:28:06 -0800, Antony Has Frothed:

If you're interested in repair a good start would be to post the manufacturer and model number. As far as the ccfl and circuit, nothing is certain when it comes to longevity.

--
Pierre Salinger Memorial Hook, Line & Sinker, June 2004

COOSN-266-06-25794
Reply to
Meat Plow

The LCD Monitor is a

BenQ FP731 17".

Not much information available (bought it because it was cheap a few years ago).

I have opened it up and haven't been able to find any bad caps or other component damage.

The ccfl are a pair of dual ccfl at the top and bottom and they are about 3mm in diameter.

Also there is some black deposits on both ends of the lights. These deposits for a ring about 1mm thick.

Reply to
Antony

I had a sony with a bad inverter board doing exactly that. Try powering the bulbs one by one using an inverter board from an old scanner. If the picture stays, you have a bad inverter, if it fades, bulb in question is bad. Most monitors have more then one lamp.

Bart Bervoets

Reply to
Bart Bervoets

I have more than one bulb, 4 to be exact - 2 in the top and 2 in the bottom.

I have taken the entire monitor apart and like I said before, I can't find any faults with the inverter circuitry.

Is it normal to have dark deposits on the ends of the CCFL tube? That is what I have and I don't know if that indicates that my tubes are bad.

Antony.

Reply to
Antony

The fault you are describing is normaly from a bad inverter board, and or the lamps are going bad. Normaly the inverter board and the lamps are changed all together at the same time.

Some LCD panels are not serviceable, while some models are. You would have to find out the type of lamps and inverter that is required for your particular model, and then shop around to get them.

The best way to have the parts, is to contact the manufacture service rep for your monitor and see if they will sell the parts to you. Normaly, the manufactures will not sell service type parts to the end user. In this case, you can find out what they will charge you to service the monitor themselves. At least, if they service it for you, there will be some type of warranty for the work done.

Considering that the new LCD monitors coming out are far improved, it may be worth to buy a new one. I am seeing them with 2000:1 contrast ratios, with speeds as fast as 2 ms. The viewing angels, and accuracy of colour tracking are also far improved. The prices have also dropped by a very high percentage.

Jerry G.

--




>
> 1)  I turn it on, it displays the signal/picture
> 2)  Several seconds later it fades out with a green tint and then goes
> black.
> 3) I need to unplug it and leave it for about a minute before I can
> turn it on again.
>
> Every time I turn it on in this state, it stays on for less and less
> time.  I guessed that maybe the CCFL is dead, but don't they usually
> last a long time?
>
> I have taken it apart and I can't see anything that is obviously burnt
> out/loose/ or just plain wrong.
>
> Any clue as to what this might be? Or what I should replace?
Reply to
Jerry G.

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