Dished lcd monitor

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yusha
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Dished lcd monitor

Post by yusha » Sun Jun 14, 2009 1:07 pm

Hi,I got a used Samsung Syncmaster 920nx lcd monitor which works fine except it seems like it is dishing everything into the center of screen.Like the lines a little bit curved.On an older monitor we were able to set the convex but i cant set it on here.Im running this with xp pro,downloaded the samsung driver and tryed the on board menu but cant adjust this problem.Is there adjustment could make on the board?Thanks for help.

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MrAl
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Re: Dished lcd monitor

Post by MrAl » Mon Jun 15, 2009 5:02 am

Hi,

Of all the monitors i have had that were CRT, they all had adjustments right on the body of
the unit somewhere. The buttons sometimes had to be hit in the right order to get to the
right adjustment, but they were always there right on the monitor body usually under
the screen somewhere.
LEDs vs Bulbs, LEDs are winning.

yusha
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Re: Dished lcd monitor

Post by yusha » Mon Jun 15, 2009 7:47 am

Thanks but have tried all the external buttons on the front of the monitor.I can make ajustments except for the convex or concave problem.

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MrAl
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Re: Dished lcd monitor

Post by MrAl » Mon Jun 15, 2009 12:12 pm

Hi,

Gee, sorry to hear that. Perhaps do a search on the web for your model?
Maybe contact the manufacturer and ask them how to adjust it?
LEDs vs Bulbs, LEDs are winning.

yusha
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Re: Dished lcd monitor

Post by yusha » Fri Jun 19, 2009 8:35 am

Help!same monitor now does nothing except for very brief splash of motherboard and then win xp as computer boots and then nothing,zero,blank.Even without video cable connect Im supposed to get a selftest feature but only a very brief (1/2 sec) splash.Any hints.

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Janitor Tzap
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Re: Dished lcd monitor

Post by Janitor Tzap » Fri Jun 19, 2009 9:36 am

Sounds like the inverter board has gone bad. :(
It drives the back lighting for the display.
That could of been causing your "dishing" effect, before it failed completely.

If it is still under warranty.
Get an RMA from Samsung.

Otherwise take it to some one who works on rebuilding the inverter boards.
Or find a re-builder that will exchange your bad board for a rebuilt one.
But from what I saw price wise, just the inverter board can run $60 - $160.

Edit: I almost forgot!
Mat Electronics has just recently gotten in a large selection of Inverter boards.
http://www.matelectronics.com/
Go have a look there.

Good Luck Yusha!


Signed: Janitor Tzap

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MrAl
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Re: Dished lcd monitor

Post by MrAl » Fri Jun 19, 2009 11:04 am

Hi again,

Oh geeze, i must have read the original post gnorw (backwards)
because i thought this was a CRT monitor.

If i realized it was an LCD originally, i would have said that something
is really wrong because i dont think they make adjustments for LCD
panels that adjust the pin cushion effect you are seeing. You see,
the pixels are built into the monitor circuit panel in the right place to begin
with so they can not be moved.
If you are really seeing a pin cushion effect (or its inverse) then something
must be wrong with the software. Could it be that really just part of the
screen was dark?

Since you now say that the monitor works for only a second then i have to
agree that the inverter board is probably bad because that would have a
built in current detection circuit to turn off the driver stage once a fault
is detected. This usually happens when an electrolytic capacitor blows out
and the way to find it is to either see one that has gushed out and maybe
brown or to measure each one with an impedance meter.
If it's not that then it could be another capacitor, or even a transistor
that is not properly heat sinked. I would bet more on the cap though,
because what happens sometimes when they go bad through aging is
that they work ok up to a lower than rated voltage, but as soon as
the voltage gets up to 'normal' for that circuit, it arcs over and that's
when the output section current detector senses an overcurrent and
immediately (very quickly) shuts down the driver section and hence the
screen goes dark.

Just to verify, when the monitor shuts off is it completely dark or do you
still see a little backlighting? Backlighting is when the screen is not
displaying anything and it is trying to display a black screen but the
backlight still shows through the polarizing filters a little. You can tell
the difference in a darkened room best.
LEDs vs Bulbs, LEDs are winning.

yusha
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Re: Dished lcd monitor

Post by yusha » Fri Jun 19, 2009 1:18 pm

No,Monitor goes off completely,cause the win xp splash isnt fully on before it stops and while it is doing that ,for the mini sec it is on,you can see everthing clearly and then nothing.

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Re: Dished lcd monitor

Post by yusha » Fri Jun 19, 2009 3:04 pm

Heyyyyyyyyy heyyy ohhhhh yesssss!!!!!!! I FIXED it.Relaced most of the electrolic caps and it works.I did see one which had heated the board abit so maybe it the one.Thanks for all advice.

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dacflyer
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Re: Dished lcd monitor

Post by dacflyer » Thu Jun 25, 2009 3:53 am

i was just going to mention that..check the caps in the power supply...

we have a monitor here that the screen at the top looks like its melting..
i think somehting is wrong with the LCD. the warmer it gets, the more it looks like its drooling..
and yes, LCD's do get screen burn also...we have several here that are burned.
and 2 that the screens look melted at the top.. LCD monitors do put out a bit of heat also..
not as much as a CRT, but still get very warm. i think they should have a cooling fan in them.

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MrAl
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Re: Dished lcd monitor

Post by MrAl » Thu Jun 25, 2009 7:32 am

Hi dac,

I was actually thinking of mounting a small fan on the exterior of one of mine, to cool it better of course.
What else i was thinking was that with my much older monitor, i was too lazy to replace ALL the caps
in that one (same problem as his monitor had) so i gutted it. What i found was that the inside had
lots of dust on it.
So another concern with a fan is increased dust buildup, but also dust buildup over time for
any monitor and how to clean it.
Anyone take a LCD monitor apart yet? (and get it back together again)
LEDs vs Bulbs, LEDs are winning.

yusha
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Re: Dished lcd monitor

Post by yusha » Thu Jun 25, 2009 8:42 am

MrAl,Im not quite sure what you mean taking a lcd monitor apart.I did .You have to in order to get to boards unless you mean the display.Well,I sure that will happen next.Oh ,My son had a Viewsonic with almost the same problem as mine and again replacing the 470 25 volt cap (only one on their)solved the problem.I cant believe it this easy.way simpler then working on CRTs.

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MrAl
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Re: Dished lcd monitor

Post by MrAl » Thu Jun 25, 2009 10:35 am

Hi again,

Oh yes, of course you must have taken one apart to fix it :smile:

I guess you had no trouble getting it back together again?

The reason i ask is because i have never taken an LCD monitor apart, yet i have taken other
LCD products apart and in particular a meter, which after taken apart the LCD glass becomes
detached from the pressure connector and it is sometimes a pain to get it to contact it
correctly again.

I guess no problems like this came up when putting it back together?
LEDs vs Bulbs, LEDs are winning.

yusha
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Re: Dished lcd monitor

Post by yusha » Thu Jun 25, 2009 12:59 pm

No prob.MrAl.Front display is wired to board with connectors and so are the three boards.Very simple.I tell you what ,I,m NOT going to leave any nonworking Lcd dispalys at the garage sales any more.

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MrAl
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Re: Dished lcd monitor

Post by MrAl » Fri Jun 26, 2009 6:04 am

Hi again,


Oh ok great. Maybe if i see one for sale i'll pick it up and experiment a little too.
LEDs vs Bulbs, LEDs are winning.

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