Monitor blackout(except for a bright line in the middle part) after ~10mins

[BunkFace]

I have a 17 inch Likom CRT monitor. It's about 4-5 years old. When I turn it on sometimes it will come on with no problems then after about 10 minutes the whole screen becomes black and there's a bright wide line in the middle part of the screen. The "Power" light is still on. I've tried it on multiple CPUs and it still happens.

Can someone give an explanation for the problem? The warranty has expired and I'm not sure if the part damaged will be worth the repair - should I just get a new one?

 

[Nodsu]

Something is broken in the vertical scan system. Depending on the flaw it can be fixed for cheap or you may have to scrap the monitor.

Take it to a repair shop and see what they say.