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Main => Monitor/Video Forum => Topic started by: stuzza on June 29, 2004, 05:51:08 am

Title: Monitor has weird colours? - Lots of pics attached
Post by: stuzza on June 29, 2004, 05:51:08 am
Finally got hold of a digital camera to get some shots of the monitor.  It is a 25" Kortek monitor.  The picture is dim and so I have ordered a Video Amp to hopefully overcome this.  However there is a blueish tinge in the top right corner and a greenish tinge in the lower left?  

I have speakers and a fluroescent light behind the marquee above the monitor, but I haven't even plugged them in yet, so I don't think they could be causing interference.

Will the Video Amp be enough to fix the picture??  Also, what resolution can i set the vertical games so there not cut off at top and bottom?  I've used the AVGA Resolution Tool, but I'm not sure what settings to put in to fix this.

The pictures below give a good indication of what it looks like.

(http://members.lycos.co.uk/stuzza12/misc/monitor/Picture033.jpg)

(http://members.lycos.co.uk/stuzza12/misc/monitor/Picture038.jpg)

(http://members.lycos.co.uk/stuzza12/misc/monitor/Picture044.jpg)

(http://members.lycos.co.uk/stuzza12/misc/monitor/Picture046.jpg)

(http://members.lycos.co.uk/stuzza12/misc/monitor/Picture048.jpg)
Title: Re:Monitor has weird colours? - Lots of pics attached
Post by: menace on June 29, 2004, 07:52:23 am
looks like it needs to be de-gaussed in a bad way :) As well it looks like you need to adjust your red/grn/blu guns to balance the colors somewhat.  In mame there is a rom called the sente diagnostic cartridge that has a nice set of color bars that can help you tune your colors--I put more info in the FAQ on this.

As far as the de-gaussing is concerned, your coil may be toast so it's not running when you fire up the machine--Ken Layton would be the best person to ask as to how to confirm this.
Title: Re:Monitor has weird colours? - Lots of pics attached
Post by: 2600 on June 29, 2004, 09:14:54 am
Actually, I would try removing the speakers and the degaussing it to see if that helps.

Remember, speakers have the magnet on the back so they don't need to be plugged in.
Title: Re:Monitor has weird colours? - Lots of pics attached
Post by: Ken Layton on June 29, 2004, 10:18:19 am
Yup, I bet those speakers are too close to the picture tube. Unless you have "shielded" type of speakers the speaker magnet is likely causing the color problem. You will definitely need to buy a manual degaussing coil and use it to degauss your picture tube. That's all your monitor needs.
Title: Re:Monitor has weird colours? - Lots of pics attached
Post by: MonitorGuru on June 29, 2004, 10:28:45 am
There also appears to be an overabundance of red and a lack of green.  

Dont monkey with any controls until you first move the speakers away at least two feet on either side of the monitor, AND degauss.  See what your picture looks like then.

If it's still red and lacking green you'll need to do some white balancing and adjust down the red bias/drive control and up the green.   You might want to look at the cutoffs too, the green cut off may be too low.
Title: Re:Monitor has weird colours? - Lots of pics attached
Post by: Harry Potter on June 29, 2004, 11:03:43 am
Finally got hold of a digital camera to get some shots of the monitor.  It is a 25" Kortek monitor.  The picture is dim and so I have ordered a Video Amp to hopefully overcome this.  However there is a blueish tinge in the top right corner and a greenish tinge in the lower left?  

I have speakers and a fluroescent light behind the marquee above the monitor, but I haven't even plugged them in yet, so I don't think they could be causing interference.

Will the Video Amp be enough to fix the picture??  Also, what resolution can i set the vertical games so there not cut off at top and bottom?  I've used the AVGA Resolution Tool, but I'm not sure what settings to put in to fix this.

The pictures below give a good indication of what it looks like.

 :o

You either live inside house-sized speakers or directly under power lines.

WOW!

You may also have the RGB lines swapped around. Had the same problem once on a Commodore 1084s monitor. That'll teach me to follow what's written in the manual.  :P
Title: Re:Monitor has weird colours? - Lots of pics attached
Post by: stuzza on June 30, 2004, 01:00:06 am
Thanks for the response.   I'll remove the speakers tonight and I guess I'll have to try and figure out how to degauss the thing?  is degaussing an easy thing to do?

The speakers I put in there are Creative Inspire 2.1 2500.  I decided to use them because of the external remote control.  Is there a way I can perhaps shield the speakers?  Or can anyone recommend another set that I could buy which would be better suited.  Perhaps some car speakers that I could still hook up to the creative sub?  It'd be a bummer to not use them after I bought them especially for the cab and went to all the trouble of mounting them!  :(
Title: Re:Monitor has weird colours? - Lots of pics attached
Post by: stuzza on June 30, 2004, 06:58:07 am
Ok, I have removed the speakers and as a quick fix I used a magnet and moved it in a clockwise way around the screen while moving backwards.  Sure enough, the blue and green colour areas that were prominent before are 90% gone!  I'll try and get hold of a proper degaussing coil so I can make sure it is 100% ok.

However, I am having all sorts of trouble trying to get the colours correct.  I can't seem to get blue to appear as a proper colour - ie. as in the pics the screen is more red and green than blue.  I've tried adjusting the R, G, B pots on the monitor board but none of them seem to fix the problem?  

Edit:  I'm an IDIOT!!  I just discovered the colour problem, I had mixed up the Red and Blue wires on the VGA cable!  Swapped them over and hey presto, I have proper colours!!!!!!  Yeah!  ;D  The colours could still be a lot brighter, so I'm now certain that I need the Video Amp just to make the picture perfect.

Thanks a million to all your replies, without you guys I'd still be scratching my head - and probably throwing large objects at the monitor by now  :P  Thanks especially to bosss7 for the suggestion of checking the wires are not swapped.
Title: Re:Monitor has weird colours? - Lots of pics attached
Post by: JoeB on June 30, 2004, 10:03:35 am
There's a lesson to be learned here..

before one installs speakers in their cab, they should place them next to the monitor, while it is on.  If any interference is seen, go get other speakers.

Shielded PC speakers are designed out of the box to be placed next to the monitor, and are the best bet for color problems.

congrats on solving your problem.
Title: Re:Monitor has weird colours? - Lots of pics attached
Post by: JAMMA Guy on June 30, 2004, 01:18:11 pm
before one installs speakers in their cab, they should place them next to the monitor, while it is on.  If any interference is seen, go get other speakers.

or just buy cancellation magnets  ;D
Title: Re:Monitor has weird colours? - Lots of pics attached
Post by: Harry Potter on June 30, 2004, 01:19:30 pm
Congrats on not giving up. I would have tossed the fu)ker off a building by now.  ;D

Happy gaming  :D :D :D :D :D :D :D :D
Title: Re:Monitor has weird colours? - Lots of pics attached
Post by: stuzza on July 01, 2004, 08:14:28 am
Update:

I managed to get hold of a professional Degausser.  I loaned it from the amusement company who gave me the monitor.  ;D

For those of you (like me!) who have no idea what a professional degaussing wand looks like here is a pic of it:

(http://members.lycos.co.uk/stuzza12/misc/monitor/degauss01.jpg)

(http://members.lycos.co.uk/stuzza12/misc/monitor/degauss02.jpg)

It worked pretty well and there is no blue or green in the corners of the screen now.  There is still a slight discolouration on the left that I can't seem to get rid of though? I'll keep tweeking and see what I can do.

A friend also suggested to use alfoil to cover the speakers as it can shield them??  Guess it can't hurt to have a go!
Title: Re:Monitor has weird colours? - Lots of pics attached
Post by: Harry Potter on July 01, 2004, 09:38:32 am
HEY! You stole my wand you f