Monitor buzzing: WG

[tmcw]

Have a monitor that's making a buzzing noise.

Code on the chassis is 13K4713.

The tube part is a Toshiba, has a code: 370DJB22

Any clues as to what could cause be causing the noise, anything can be done to stop the noise, is it a sign of an imminent failure?

Picture on monitor is pretty much perfect.

 

[Shavenyak]

It may be the flyback getting ready to go. I've got two that are doing this. Waiting on my flyback order to arrive.

 

[RetroHacker]

It could be one of several things. A certain amount of buzzing is normal, but you shouldn't be able to hear it when in front of the monitor, or outside the cabinet. It could be the flyback vibrating slightly at the scan frequency - although this is usually more of a whine. A flyback whining isn't necessarily about to fail, either. Sometimes the core just gets a bit loose in the windings.

Use a piece of rubber hose as a stethescope to find what component is buzzing. Gently poke the flyback and other components with a plastic pen barrel to see if you can change or stop the buzzing.

-Ian

 

[tmcw]

Thanks for the replies.

I used a pipe to pinpoint where the buzz is coming from, and it's actually coming from the power supply transformer. I thought it was coming from the monitor initially, because when I disconnected power to the monitor, the buzzing stopped (and everything is cramped together inside a cocktail cabinet, so difficult to pinpoint exactly where the noise was coming from). But it seems that when the transformer is under the load of the monitor, it begins to buzz.

It dampens the buzz a little when I poke it with a wooden spoon, but it's still quite loud.

Does it sound like something that could be fixed? Or am I looking at replacing? Is it a sign that it's on it's way out, and if so, could it take anything else out with it?

Transformer is part of Williams power supply.

 

[RetroHacker]

What game is this?

On some games, the monitor isolation transformer is part of a single, large power supply transformer. (Robotron, etc), and others have an isolation transformer for only the monitor (and coin door lights, IIRC) and a switchmode power supply (Smash TV)

Sometimes the laminations get a bit loose. Some power transformers are held together with big bolts - tightening them can help make them quieter. Cheap isolation transformers are held together with metal clips - these can be clamped tighter. It's such a common problem that Bob Roberts has a whole page about how to fix them : http://www.therealbobroberts.net/iso.html

-Ian

 

[tmcw]

It's a Stargate, essentially, the insides are the same as this Defender:

http://www.appolo.com/projects/defenderct2/P011570.jpg

My transformer looks the same as the one under the speaker in the picture above.

Thanks for the link and suggestions, good to know that it may be possible to refurbish it. I'll take the board that the power supply is mounted on out at the weekend, and have a good look at it, tighten up any screws or bolts.