Monitor Questions

[bjames901]

I recently purchased a cocktail table and had it worked on. I was told that it needs a new capacitor kit which would fix the discoloration in the right corner of the screen. The guy claims that he degaussed the thing and improved it slightly, but I can't tell that much of a difference. The thing is when I unlatch the monitor and move it further away from the other electronics, the picture looks damn near perfect with rich red colors throughout. Can anyone help me figure out how to diagnose this puppy. I'm not very technically savvy so I don't want to mess anything up in the cabinet. I'm thinking it may be an issue with the speaker. I don't even know how to move it because it looks bolted in, but I'd like to try and figure out a solution to this without gutting the thing.

Thanks for the help.

[boardjunkie]

Remove the speaker(s) and see what happens. My guess would be that someone replaced it/them with types that have a large ceramic magnet. That will really screw with yer monitor in a CT game.

[bjames901]

Well something interesting happened. I removed the speaker and tried to isolate it by moving it outside the cabinet (I didn't want to screw up the soldering or wires so I didn't literally detach it). I then turned on the machine and I had the same problem so I reattached the speaker and now the color has gotten worse.

[grantspain]

check for a manual degauss switch

[boardjunkie]

Yea...we need to know what kind of CT this is. The Nintendo CTs had a manual degauss button, some Segas did as well. If its got a wells gardner or electrohome (or similar) monitor with auto degauss then there's a problem with it....its not working. But.....my statement holds true.....keep large magnets away from CRT monitors.....

[bjames901]

So after turning off the game and coming back to it, the color looks the way it did before reattaching the speaker, the way it looks in the attached photo. The monitor chasis is a G07 CBO. The monitor is an RCA. I'm not sure where to find the actual model of the monitor. It sounds like it doesn't have an auto degauss. Could it benefit from some sort of isolation transformer shield. Someone suggested that would help with the interfering electronics.

Thanks for the help.

[MonMotha]

Looks like a standard Midway cocktail with a Electrohome G07, to me.  That should auto degauss, but there's a good chance something's broken and preventing it from working.

For grins, also check that the purity/convergence rings on the neck are not loose.

[boardjunkie]

Yep.....the tube is made by RCA, but the monitor model is Electrohome GO7.

You need onna these:
http://cgi.ebay.com/GC-Tool-Computer-Monitor-Television-Degaussing-Coil-/350476846048?pt=LH_DefaultDomain_0&hash=item519a0c43e0

Heres one in action:

[bjames901]

Do you think this is all it really needs is another degaussing? The guy said he already did one on it. That would be awesome if that's all it takes.

[boardjunkie]

If the auto degauss don't work, everytime you move the game it needs to be degaussed. If a strong magnet gets too close to it, it needs to be degaussed. Monitor tubes are incredibly sensitive to external magnetic fields. You may want to have it looked at by someone who knows their way around old style tv's or a veteran game tech. The auto degauss obviously is not doing its job. Its prolly either cracked solder or a failed thermistor. I don't think I've ever seen a coil go bad in my 20 some years of repairing monitors.....

[MonMotha]

Even if the integrated deguass is working, it's possible that it isn't strong enough.  The built-in degauss coils are fairly weak compared to the dedicated, handheld ones.  Sometimes it just takes a good manual degaussing to fix things.

Any time you move something, even just turning it in place, you can introduce gaussing artifacts from stray magnetic fields.  It's perfectly normal.  In some cases, there's some stray magnetic field nearby the location chosen, and you can't fix it with any amount of degaussing: you have to correct the ambient problem.

Note that the handheld coils can get pretty toasty during operation, so be careful with it.  Also look up the "degauss dance" to improve results.

[bjames901]

So I borrowed a degaussing coil from a guy at Twobits and it improved the quality of the right side of the monitor. Still though, even after degaussing, the color is more vibrant when I move the monitor away from the cabinet. I can live with it this way, but I'd like to get it perfect.

[boardjunkie]

Take a pix of the speaker and post it.