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Author Topic: tv discoloration  (Read 2489 times)

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Trimeister

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tv discoloration
« on: July 23, 2002, 07:08:28 pm »
Hello Everyone,

I'm new to this forum but I'm here because I have an issue with my tv and wondering if you guys can help me out.

I recently finished with my upright cabinet using a rotating 20" Apex tv. While in vertical mode the color in the corners are not the same. Its different than the original game. I've noticed that when I rotate it back vertically slowly the color came back slowly. Looks like  the color changes depends on the angle. I was told that it could be the magnet from speakers because I do have 4 small speakers(Cambridge) on each corner of the cabinet. I removed the speakers but that wasn't it. The only thing left I could think of is that the tv motherboard doesn't rotate when the tv does. Could that have any effect?

PS-the color in any horizontal games are fine it only affect vertically.

Please help, any advises are greatly appreciated,

Thanks,
Trimeister :-\

MameFan

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Re:tv discoloration
« Reply #1 on: July 23, 2002, 09:11:52 pm »
It's not due to the speaker (unlikely, especially if they are shielded computer speakers).

Actually, it's due to the Earth magnetic poles themselves.

When you twist a TV or computer monitor (even on a flat surface, not even rotating to portrait mode), you change its orientation with the earth's magnetic fields.

Turn your TV, then turn it off for at least 20 minutes (some TV's as little as 5 minutes).  Then turn it back on.  It should re-activate the "Degauss" circuitry and demagnetize the tube IN ORIENTATION TO THE EARTH in the direction you have it.

But if you change it back to horizontal, you will again encounter discoloration--but now in that mode, unless you let it degauss (demagnetize)

Trimeister

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Re:tv discoloration
« Reply #2 on: July 24, 2002, 01:11:57 am »
Thank you MameFan.

I'll give it a try.

SNAAAKE

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Re:tv discoloration
« Reply #3 on: July 25, 2002, 07:24:31 pm »
i know i am jumping on this,but i just got a small monitor problem today..damn damn damn..i mount the monitor correctly..its horizontal...while i was drilling the wood i bumped into monitor with my drill..its only minor..but then i got color disorder,(a spot where i am missing coler and odd colars are there) on the upper left corner...i also got some speakers installed..no idea if they are shielded or not..i just broke open a pair amlified speaker then screw them in a piece of wood..any idea anyone???also what is disgussing coil..why should i buy one.will this coil thing do the trick..i dont know much about monitors..i know other stuff really well..but kinda week in the monitor part..afterall..i dont like enjoying monkeying around inside the monitor and get killed :-\

MameFan

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Re:tv discoloration
« Reply #4 on: July 25, 2002, 11:32:47 pm »
> bumped monitor...

Actually, your bumping the monitor likely DIDN'T cause the color problem.

You see, when you have a motor, it works by creating a magnetic field (with electricity and an electromagnet) around a rotating fixed magnet. It causes the inner piece to spin, and thus turning the drill.

You actually magnetized the side of the tube (likely the metal shadow mask inside the front of the tube that separates the RGB guns to hit the right phospor points).

You must now DE-MAGNETIZE it.  

Is this an arcade monitor or a TV set or Computer monitor?

MOST should already have a degaussing circuit and coil.. Look for it wrapped just behind the face of the tube (somtimes on the widest edge, sometimes just back a bit where the tube starts slanting inward towards the back). It's a pair of wires wrapped in what looks like tons of black electrical tape, and it loops around the entire tube.

If you shut off your monitor for a long enough time, then back on, it should reactivate the degauss circuit and try to remove more magnetisim

If you magnetized it too much, (or it's lacking deguassing capabilities) then you'll have to either buy a degaussing coil or, if you have one, try a BULK TAPE ERASER.   The trick is to hold the coil or eraser away from the set, then bring it inward towards the set (you might aim just at the corner that's bad) and swirl it around a bit, then pull it at least 6 feet away, turn it, then turn it off.

Do NOT turn it off while in front of the tube directly. It will then reapply the magnetic field, doing nothing.


If this doesn't work, then as a LAST resort, you can try to "magnetize" the tube in the bad corner in the OPPOSITE direction.  Basically take a big speaker magnet (break apart an old car 6x9 speaker). Move it up to the monitor (with it on preferably so you can see your results). and then with a solid color screen that is bad in that corner, swirl the magnet around and pull it away.  If it got worse, then flip the magnet over and try again.

I've fixed a couple monitors this way.

Remember... Power tools contain features that create magnetic fields.  NEVER use them (even battery operated ones) next to a picture tube... You will end up magnetizing it!


Re: Speakers.

To test if speakers are shielded or not, take a TV or monitor that you dont care about.  Turn it on with a solid color screen.  Move the speaker (especially the back) towards the monitor.  If it produces a Purple or Green tint and moves stuff on the screen, then it is NOT shielded.    If it does nothing, then it is shielded.

SNAAAKE

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Re:tv discoloration
« Reply #5 on: July 26, 2002, 12:34:18 am »
MAN HOW DUMB AM I >:(

the monitor was on while i was working on it..that what happend before too..i was working while the thing was on...it was for someone else..i was trying to help a really dumb friend of mine...

i know i am bothering you so much mamefan..but please help...

if i buy that disgussing coil..will that fix this?
i do see the black wraping thing around the monitor..what i do with that..please explain it little clear..i am not very good with monitors so i did not understand what you tried to explain...also if i try the magnet,is there any chance i make it even worse?after all..i do not wanna make it even worse while i try to fix it...PLEASE POST...much thanks in advance..this is why this board kick serious --I'm attempting to get by the auto-censor and should be beaten after I re-read the rules--..i did not ever think about what i did(working while monitor on)..anyways..thanks again.

MameFan

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Re:tv discoloration
« Reply #6 on: July 26, 2002, 10:35:09 am »
Actually, it didn't matter if the tube was on or not when you used the drill by it.  It magnetizes it either way.  (When it's on, you just have the ability to see the effects immediately)

The degaussing coil around your tube is there and works automatically every time you turn on your monitor from a "cold" start. (e.g. like after it's been off at least 5-20 minutes, depending on design).  That's why most computer monitors, when first turned on give a lound "thunk" sound and the screen wavers a bit. That's the monitor sending 120 volts thru that coil to help remove any magenetism that built up on the metal mask.  (side note: This gets built up normally just because of the earth having magnetic poles. However this is a minor amount and not like what you did by putting a large amount of magnetism towards one side of it)

My FIRST suggestion is to simply turn on the monitor, then turn it off, let it sit off a good amount of time to cool down the circuitry that activates the degauss, then turning it on again.  Basically turn it on, then off for 15-20 minutes (or longer, depending on monitor), then back on.  Do this for a day or so.  See if it makes the color/bending less in that corner.

(You see, it works by sending a ton of volts through the coin when first turned on, which, in turn increases heat in a resistor. This resistor shuts down after a few seconds, but must cool completely, and be activated again when it turns on the next time. Without this circuitry, it would constantly be degaussing the screen, causing it to wave and change colors while you used it (and heating up the coil like a light bulb and burning up besides! :( ))


If this doesn't work (assuming the circuitry is working), then your next step is to get a separate degaussing coil or find someone (or buy) a Bulk Tape Eraser like from RadioShack, sometimes you can find them at thrift stores too for a few $, I know one near me had one a few weeks ago for $5.

Follow my instructions in the previous reply on how to use an external degauss coil  or tape eraser.  You might want to also check out Bob Robert's instruction pages (www.therealbobroberts.com) and click on "you need help" link at the bottom.  I think he talks about how to manually degauss things.

Finally if all that fails, try the magnet trick.  Start first with something small, like a small poster magnet or fridge magnet instead of the massive speaker magnet.  Then you cant ruin it too much, but it might not remove it all.  Yes, you CAN screw it up so bad you might not get it out... However, I've gotten some bad bending/color problems fixed by using a broken sliver from a ring shaped speaker magnet (about 1/6 th of it's size) on a 19" arcade monitor a couple times.  If you go too far in one direction (e.g. turning purple to green), simply flip the magnet over to use the other "pole" and then undo it the other way.

Good luck.

SNAAAKE

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Re:tv discoloration
« Reply #7 on: July 26, 2002, 01:43:24 pm »
well you wanted to know what the monitor was..its 19" eygo..i just finished my cab and there is this new problem  :'(..i will post about how it turned out..i tried with magnet..nothing but i did make some other spot little darker..the color are okay i think but the spot i was talking about has like a missing color of some sort..i will email you with how its going...thanks for the help ;)

SNAAAKE

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Re:tv discoloration
« Reply #8 on: July 27, 2002, 01:32:32 pm »
MAMEFAN,
if you are reading..i did try the magnet thing..it made it worse...so what i happend was that the black wraping around the monitor just not in place..somehow it moved by itself...now i just wanted to know if i can just move those black cord and just use duck tape or something to put it back in place..if you are reading...please post..or if you have AIM,ICQ,yahoo messenger...please let me know..i am very sad with the monitor overhere..thanks a lot man.. :D

x-wing

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Re:tv discoloration
« Reply #9 on: July 28, 2002, 02:12:06 am »
sNnnakE,

You should put the deguassing coil back into it's proper position.  Duct tape should hold it in place just fine.  You shouldn't be using a magnet unless you know what you are doing.  It sounds like you kinda screwed up your monitor because you don't know how to deguass with a magnet, but if your degaussing coil is put back where it should be, everything should work out eventually after enough cold starts.

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Re:tv discoloration
« Reply #10 on: July 28, 2002, 02:16:50 am »
here we go again..i did fix it already today....not using your help of course..i just put them back in place..and that was it...before you even wrote...

x-wing

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Re:tv discoloration
« Reply #11 on: July 28, 2002, 02:27:21 am »
Sssnake -

There was no mention that you already had the problem fixed when I posted the reply.

It's nice to see that you appreciate answers to your questions, though.