HELP! my 22" CRT Monitor sparkles!

[Yoto]

Hello guys, i was using my computer when suddently my LG N2200P Monitor (4 yeard old) started to sparkle at the top and making a Bzzzt like noise. I immediatly turned it off, and its off ever since.

I opend it now but i cant find any trace of burn components neither it smells burned...i´m tempted to try to turn it On again...

Anyone had any experience with this kind of problem....
The anode on top seems to be firmly attached to the CRT tube...

"Damn you Stan Lee"

[jmmijo]

That would indicate that the video and/or the high-voltage circuit has taken a hit, could be a regulator component or some chokes/coils on the circuit board possibly.

I would suggest a local tech to diagnose and see if the repair charges are worth it or not.

I bet the CRT is fine just need to find the faulty component/components on the board and replace as neccessary.

Also, are you using this CRT for output from any Amiga equipment due to supporting 15KHz sync signals ???

Then I would say it's worth repairing if not then I would suggest getting a 22" Widescreen LCD, these are way down on pricing now a days

[Yoto]

Thanks Jimmijo i will do that.
The noise seemed to came from the anode area, its rainning for almost 2 weeks now and the humidity in my office rounds the 90%. I dont know if a combination of dust and moisture in the coils done the trick...
A regular LCD does not support Quad-Buffer...and that just sucks, i wish it did...

[DH]

As jmmijo says, fix it if you're using it for the miggy otherwise 22" Widescreen LCD

22" Widescreen Samsung SyncMaster 226BW is what I have, and at the time of purchase, it was the best monitor, in loads of reviews on the net, for it's size and price. I like to thoroughly check first before I buy. I was going to get the equivalent Samsung Pebble, but the reviews said it was crap 'cause of the cheaper components Samsung decided to use.

[Yoto]

I too have a Sammy 22" Syncmaster 226BW, but it does not support the quad-buffer display...

[FOL]

Originally Posted by Yotoxionomai

Thanks Jimmijo i will do that.
The noise seemed to came from the anode area, its rainning for almost 2 weeks now and the humidity in my office rounds the 90%. I dont know if a combination of dust and moisture in the coils done the trick...
A regular LCD does not support Quad-Buffer...and that just sucks, i wish it did...

If its making a crackling noise from the anode cap. Then it more than likely a hole in the cap or its not connected correctly.

Make sure you discharge it before messing with the cap, if your going to look at it.

It could also be the LOPT, could be cracked, causing it to arc. This would give the effect of sparkling.

[Yoto]

Thanks FOL, yes exactly, its a cracking sound, i plugged it again...i know...i am....and it makes this noise from the lower left (with the screen facing me). This seems to be the place where the line output tranformer is...i just cant explain the sparks i saw earlier coming from its top but the noise seems to come from the left side, maybe it just overloaded...i gonna take it to a technician who also fixes TV´s...

[FOL]

Originally Posted by Yotoxionomai

Thanks FOL, yes exactly, its a cracking sound, i plugged it again...i know...i am....and it makes this noise from the lower left (with the screen facing me). This seems to be the place where the line output tranformer is...i just cant explain the sparks i saw earlier coming from its top but the noise seems to come from the left side, maybe it just overloaded...i gonna take it to a technician who also fixes TV´s...

Its proberly due to old age. Used to see it alot with sony tv's, the lopt would crack due to old age (sometimes due to the line output transistor). The resulting crack would allow it to still operate, but it would arc to the deck. It proberly has some other components gone in the line section too.

If you get it fixed, get them to check the focus. If they are cool an have a crt tube booster (if its an oldish set/monitor), as them to clean balance guns of the tube. Its what I used to do without being asked for free.

The picture will be as bright and clear as the day it was bought, .

If it is deffo the LOPT, hope and pray you can still get it or a replacement.

[rkauer]

The problem is called electric erosion: it frequently happen in high voltage systems.

It is a form of dielectric degradation and the only solutions are:

1- re-make the insulation on the offended parts;

2- replace the problematic parts.

[jmmijo]

@Yoto, what do you mean by Quad-Buffering ?!?

Is this something in the video input curcuitry or what ???

Not sure I've heard it applied to CRT's, just Intel CPU's as they are Quad-Pumped or clocked if you will. Maybe this is what you are referring to, quad-clocked ???

All I can say is my old 19" CRT was starting to go dark on me, I replaced it with an Acer 22" Widescreen and have never looked back, my display only has an 8ms refresh but none of my games ever appear to streak or ghost

[FOL]

Originally Posted by rkauer

The problem is called electric erosion: it frequently happen in high voltage systems.

It is a form of dielectric degradation and the only solutions are:

1- re-make the insulation on the offended parts;

2- replace the problematic parts.

Indeed, as a makeshift repair, we would hot glue the crack. This allowed us to work on to find all faulty parts, before replacing lopt and faulty components.

[jmmijo]

Originally Posted by FOL

Indeed, as a makeshift repair, we would hot glue the crack. This allowed us to work on to find all faulty parts, before replacing lopt and faulty components.

Good Idea, you use a temp patch job to find the root cause/causes and fix that then get back to a permanent fix

[Yoto]

@ jimmijo

Quad Buffered Stereo hardware support is present in high end cards like ATI Fire, nVidia Quadro, 3Dlabs Wildcat and others. Drivers for these cards provide OpenGL stereo API. Software like utilities and games can access this quad buffered stereo through the provided OpenGL stereo API, infortunently finding a suitable CRT capable of displaying 1280x1024 @100 Hz is each day more difficult, only NEC and LG seem to have this models available.

[Yoto]

rkauer was right there was a small hole in the anode red cable that connects to the LOPT, high voltage was leaking to the metal plate surrounding the chassi, i patched it with hot glue and some rubber sleeve, it worked!
The monitor started to work, infortunently the discharge seems to have affected some part of the circuit.
Some resolutions are no longer available or just refuse to display turning all screen black.

1280 x 1024 @ 85 Hz is ok but unavailable @ 100 Hz
1280 x 768 @ 100 is ok but unavailable @ 120 Hz
1152x864 @ 100 is ok but unavailable @ 120 Hz (im currently using this one)

The best one would be 1280 x 1024 @ 100 Hz, Since its the native format of the software i´m working with. I could try to repair it but i dont even have a clue of what is causing this...

[FOL]

Originally Posted by Yotoxionomai

rkauer was right there was a small hole in the anode red cable that connects to the LOPT, high voltage was leaking to the metal plate surrounding the chassi, i patched it with hot glue and some rubber sleeve, it worked!
The monitor started to work, infortunently the discharge seems to have affected some part of the circuit.
Some resolutions are no longer available or just refuse to display turning all screen black.

1280 x 1024 @ 85 Hz is ok but unavailable @ 100 Hz
1280 x 768 @ 100 is ok but unavailable @ 120 Hz
1152x864 @ 100 is ok but unavailable @ 120 Hz (im currently using this one)

The best one would be 1280 x 1024 @ 100 Hz, Since its the native format of the software i´m working with. I could try to repair it but i dont even have a clue of what is causing this...

The golden rule, is Visual Checks, .
Look at all the components, maybe some are burnt. Then you have your starting point. It is harder without a service manual, but if you can hold of 1, even better, .

Glad my hotglue trick worked for you, but as I said, thats only a temp fix. I wouldnt personally leave it like that.

[Yoto]

@ FOL
Yes it worked, but due to the metal plate proximity i guess it will try to cut thru again...someday in a distant future...i hope!
I´ve put a thick rubber sleeve and insulation tape to form a big chunk (1 cm).
I tried to look for damaged components but found none, i dont know whats causing the resolutions to fail. Alas i found something new, when i turn the monitor On, the picture is not a box, instead is pinched on left and right side.
I leave it On for a while and slowly returns to normal. This must be a damaged component indeed, anyway its probably too much for me to handle, i will try to find someone to repair it.
Thanks to you all guys!!!

[jmmijo]

That be the High-Voltage Circuit Yoto, you need that anode working correctly to deflect the electron beams heading from the plates in the neck of the CRT to hit the correct lines on the phosphar coating.

When that high-voltage is not quite adequate, then you get a distorted picture on the CRT screen.

So have you checked with LG to locate any local service centers ???

Also, are you sure that an LCD with DVI inputs wouldn't work as well as this CRT ???

[Yoto]

@ jmmijo
Not yet, but i will try to check with local LG rep center...High voltage scares the hell out of me!!!
About LCD with DVI input, whell, i tested with my 226BW and it seems to display only one image, it should be running two in multi-frequency. LCD have no refresh rate it seems, and its impossible to display two images in the same cascade sequence.
It would be a dream come true (quad buffered LCD), this 34 kg´s behemoth almost broke my back in the other day, thats why i was trying to repair it....

[jmmijo]

Yeah, I hear you on the High-Voltage, just remember to unplug the power cord then use a ground cable with an alligator or banana clip and a long insulated probe at the other end.

It will discharge the anode to ground, just get under that plastic/rubber cap and wiggle until it zaps, I know it sounds bad but back in my old TV high-school shop class, this is what we did and remember we were working on a lot of old TUBE style CRT Chassis'

Also, check out this Google search, may help you out

Quad Buffered LCD Display

[Yoto]

These look nice!
http://www.vrlogic.com/html/stereo_3d_lcd_displays.html