Apple 13" Monitor failing

[beachycove]

I have a 13" 640x480 Apple-branded CRT monitor here connected to an AWS95 server, which I start up occasionally to do network software installations and so on. On Saturday past the machine ran unattended for most of the day with the screen on, and when I went to shut it down, the screen had faded and grown fuzzy or washed out. By that stage was more or less impossible to read the menus. I just started up again a couple days later and the screen is back to being crystal clear.

What would cause a screen to fail in this way? Caps or something less repairable?

I like this little CRT and would like to keep it around if possible. Nice shape, compact, and hitherto well behaved.

 

[techknight]

I would almost need to see a picture of what your describing. 

CRT Monitors are very complex little devices and it can be many different things to cause those symptoms. 

Could be capacitors, could be the video amplifier IC, could even be the flyback itself. 

 

[beachycove]

I will post a pic once I get the chance, but I have to correct a mistake in the original post first: it's actually a 12" RGB, the one that runs at 512x384.  I thought the thing was connected to a different machine, but discovered yesterday that it was not.

Nice little screen, though, and ideal for a server like the AWS95 for my purposes. I'd like to keep it running if possible.

 

[techknight]

Ohh ok, thanks for clearing that up.

These particular monitors are KNOWN for capacitor issues, so that is likely the cause. Sometimes the flyback housing can crack and start developing arcing points, but youll smell the corona it gives off if this is happening. 

More than likely though, you have bad caps, especially the two or three near the horizontal drive stage. 

 

[beachycove]

Thanks!