NEC LCD monitor worth fixing?
 

I have a 2-year old 17" NEC LCD Monitor (LCD1735NXM), which has
developed a faint buzzing sound, along with the screen going completely
pink intermittently. When I tap on the case, the sound changes slightly,
and the screen goes back to normal for a time.

I have an electrical background, but before opening the monitor, I thought
of getting some ideas whether this sounds like a bad soldering connection,
which may be fixable, or whether this could be the sign of something else,
and not worth fixing. Thanks for any feedback / experience someone may
have with these monitors. Ken

NEC LCD monitor worth fixing?
 

"Ken" wrote in message
...
I have a 2-year old 17" NEC LCD Monitor (LCD1735NXM), which has
developed a faint buzzing sound, along with the screen going completely
pink intermittently. When I tap on the case, the sound changes slightly,
and the screen goes back to normal for a time.

I have an electrical background, but before opening the monitor, I thought
of getting some ideas whether this sounds like a bad soldering connection,
which may be fixable, or whether this could be the sign of something else,
and not worth fixing. Thanks for any feedback / experience someone may
have with these monitors. Ken

With a background, you should be able to work on it. Tap on local areas
once it is open. Does tapping ever cause the symptom? If it does, it is
going to be a lot easier to find the area of interest.

Look closely at all connectors and sockets once it is open. Tap them and
wiggle them.

Also, flexing circuit boards with an insulated tool is a good way to find
intermittents. Cold spray is also used, but I doubt it will be useful in
your situation.

NEC LCD monitor worth fixing?
 

On Thu, 1 Mar 2007 15:06:39 -0500, "Ken" wrote:

I have a 2-year old 17" NEC LCD Monitor (LCD1735NXM), which has
developed a faint buzzing sound, along with the screen going completely
pink intermittently. When I tap on the case, the sound changes slightly,
and the screen goes back to normal for a time.

I have an electrical background, but before opening the monitor, I thought
of getting some ideas whether this sounds like a bad soldering connection,
which may be fixable, or whether this could be the sign of something else,
and not worth fixing. Thanks for any feedback / experience someone may
have with these monitors. Ken



IMHO, probably a bad wire on a connector. I'd pull it apart and check
the connectors (the VGA input) wiring first.

The buzzing may be the backlight inverter. I'd guess it is not
related.

NEC LCD monitor worth fixing?
 

Ken wrote:
I have a 2-year old 17" NEC LCD Monitor (LCD1735NXM), which has
developed a faint buzzing sound, along with the screen going completely
pink intermittently. When I tap on the case, the sound changes slightly,
and the screen goes back to normal for a time.

I have an electrical background, but before opening the monitor, I thought
of getting some ideas whether this sounds like a bad soldering connection,
which may be fixable, or whether this could be the sign of something else,
and not worth fixing. Thanks for any feedback / experience someone may
have with these monitors. Ken





Sounds like the backlight tube is bad. The mercury depletes with age and
you can be left with a dim pink screen. This also changes the electrical
characteristics of the lamp which may result in the inverter buzzing.

NEC LCD monitor worth fixing?
 

On Mar 1, 7:33 pm, James Sweet wrote:
Ken wrote:
I have a 2-year old 17" NEC LCD Monitor (LCD1735NXM), which has
developed a faint buzzing sound, along with the screen going completely
pink intermittently. When I tap on the case, the sound changes slightly,
and the screen goes back to normal for a time.

I have an electrical background, but before opening the monitor, I thought
of getting some ideas whether this sounds like a bad soldering connection,
which may be fixable, or whether this could be the sign of something else,
and not worth fixing. Thanks for any feedback / experience someone may
have with these monitors. Ken

Sounds like the backlight tube is bad. The mercury depletes with age and
you can be left with a dim pink screen. This also changes the electrical
characteristics of the lamp which may result in the inverter buzzing.

But tapping would not change the backlight tube mercury or anything
else within the backlight. Sounds like the previous posters were on
the right track.

H. R. (Bob) Hofmann

NEC LCD monitor worth fixing?
 

hr(bob) wrote:
On Mar 1, 7:33 pm, James Sweet wrote:

Ken wrote:

I have a 2-year old 17" NEC LCD Monitor (LCD1735NXM), which has
developed a faint buzzing sound, along with the screen going completely
pink intermittently. When I tap on the case, the sound changes slightly,
and the screen goes back to normal for a time.

I have an electrical background, but before opening the monitor, I thought
of getting some ideas whether this sounds like a bad soldering connection,
which may be fixable, or whether this could be the sign of something else,
and not worth fixing. Thanks for any feedback / experience someone may
have with these monitors. Ken

Sounds like the backlight tube is bad. The mercury depletes with age and
you can be left with a dim pink screen. This also changes the electrical
characteristics of the lamp which may result in the inverter buzzing.


But tapping would not change the backlight tube mercury or anything
else within the backlight. Sounds like the previous posters were on
the right track.

H. R. (Bob) Hofmann



Oops, I missed that part. Yeah look at the inverter if it looks like the
backlight is going pink, otherwise look for signs of cracked solder
joints or loose connectors.

NEC LCD monitor worth fixing?
 

Thanks for everyone's input! Ken