WG 4900 Folding/Walling and Flyback is whining. [w/ Video]

Madaracs

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WG 4900 Folding/Walling and Flyback is whining. [w/ Video]



I started a fresh thread here since there are a couple of issues with this 4900 I have. I talked about a couple previously here.

I get some folding/walling on the right side of this monitor. In addition, even after some fidgeting around the flyback continues to make noise.

First, if I replace the flyback I'm told the whine will go away, but I was wondering if it might also fix that folding issue? Or is there another cap/resistor or diode I should replace as well?

Second in the video I point out I frequently have to degauss this bad boy. Why would I constantly have to degauss this thing to maintain the color uniformity? Bad shielding in my overhead speaker perhaps?

Reading the forums I see the 4900 is really a beloved monitor. So I'm glad I have it and I'm looking forward to getting it running tip top.


~*~*~
Cheers and Happy New Year everyone.
 
changing that flyback isn't going to make that fold go away. Its hard to hear a wine in the video, that sounds more like a sizzle which would indicate a high voltage leak.

You might want to pull the chassis and make sure that all the caps that were replaced are the right values.

That degaussing thing could be caused by a high voltage leak, a bad shadow mask (internal to the tube) or the yoke is sliding around.

EDIT: Forgot to mention. If you do have flyback whine sometimes you can shove a toothpick down inside the transformer to hold the ferrite still. Dont push too hard though, you dont want to break that core.
 
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the fold over is usually a cap problem.

but if the caps have been replaced i would check all of them for proper UF and voltage ratings plus their polarity.

as far as the hiss goes as suggested it sounds like a HV leak.

i would clean all around the anode hole and the cup to remove any debris and moisture that could have gotten in there.

also as suggested try the toothpick.

Peace
Buffett
 
One quick thing about the HV leak. I've been able to get away with using silicone to plug the hole for a while. Its not recommended but it will work in a pinch but you have to let it set before you power the monitor back up. Turn the lights off in the room and look at the flyback area closely while the monitor is power up. Chances are you will see a faint blueish/purple haze. Thats your leak. Seal it with the power OFF!

Theres also this stuff that was called "high voltage dumdum" by old TV guys. Its really thick black looking silly putty stuff. That will seal the hole until the flyback is ready to blow up.
 
If you seal it with RTV, make sure you allow it time to cure and release all the "volitile organic compounds" or it could flash out in a nice little fireball.

Yep, nothing like fried flybacks to really spoil an otherwise okay day.
 
I think I'm just going to order a cap kit and flyback. It's like $40 for both. Then I'll make sure the caps are all good and have the right ratings and replace that flyback rather than try and make it work which may in turn cause me more trouble anyway.
 
If you seal it with RTV, make sure you allow it time to cure and release all the "volitile organic compounds" or it could flash out in a nice little fireball.

Yep, nothing like fried flybacks to really spoil an otherwise okay day.

FWIW, I've never had this happen and I've powered monitors back up immediately after plugging a hole in a flyback with RTV.

It is good to wait though. :)
 
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