[SOLVED] Lines on my VGA monitor

[Nodoyuna]

Hi

I've noticed my VGA monitor (Hantarex CT28EV) has developed lines on the screen

https://imgur.com/VGhuupz

This lines appears with only the monitor plugged with no video source

What can be the source for these lines? Can be fixed somehow?

Thanks in advance

 

[Frank_fjs]

Nothing out of the ordinary, they're just the ray trace lines.

Usually happens when the screen pot (brightness) on the chassis is dialled in too high.

 

[Nodoyuna]

Nothing out of the ordinary, they're just the ray trace lines.

Usually happens when the screen pot (brightness) on the chassis is dialled in too high.

Thanks for the answer

Oh, I thought there was a problem with the CRT...

So, if I put a lower brightness, this will be "fixed"?

There is a knob for brightness and contrast on the back. Can I check from there or do I need to open the monitor and move the brightness pot on the inside?

Thanks in advance

 

[Frank_fjs]

Be very careful adjusting pots on arcade monitors.

1) They may be old and brittle, one wrong turn and game over.

2) They're not really designed for continuous adjustment, they're really designed for initial adjustment and then to be left alone. Set and forget.

I need to warn you as I don't want to be responsible for any damage to your monitor. Sometimes things are best left alone, if it's working don't try to fix it philosophy.

That said, if it appears fine with a signal I wouldn't touch a thing. If you are seeing these lines when a signal is present, then yes, turn down the brightness pot. This should be all that's necessary, if not then you will need to locate the 'screen' pot on the chassis and slowly and gradually turn it down until the lines disappear.

The screen pot is like the overall adjustment range. It dictates the range of the brightness pot. Think of it like having a sound pot on an arcade board (the screen pot on this analogy) and the volume control of your amplifier (brightness pot). If the sound pot is turned down fairly low, the amplifier volume control will have a limited response. Conversely, if the sound pot is dialled in to the maximum setting, the amplifier volume control won't have much range, it will begin very loud at the lowest point and get extremely loud with every little turn upwards. So the two pots need to be adjusted accordingly for an acceptable range of adjustment.

Hope that makes sense.

 

[suverman]

You might want to check the brightness knob on the flyback transformer as well. My chassis flyback brightness was driven way too high and I dialed it down from the flyback transformer - that removed the lines for me.

 

[Nodoyuna]

I need to warn you as I don't want to be responsible for any damage to your monitor. Sometimes things are best left alone, if it's working don't try to fix it philosophy.

Don't worry... If I finally try to fix it, it will be my fault is something goes wrong

In fact, the question is mostly about if these lines can damage the monitor or are bad for it in the long run... They're expensive monitors and I'd like to be sure that there is nothing wrong with it

I'm pretty careful and I won't venture in trying to adjust the internal pots of the monitor if it's not really needed

When there is image on the screen, be it a movie or any console, I'm getting other lines, I don't really know if they're normal or not...

https://drive.google.com/file/d/1a59OCiW3Ny2hsP1ndsNhWsTp5n_QaqLj/view?usp=sharing

Please check...

Thanks in advance

 

[Nodoyuna]

Hi

So, yesterday night I opened the monitor, and now the lines issue is fixed

It was the first time I was seeing the inside of a tube monitor, so I was lost at first, but I was able to locate the SCREEN pot and lowered it a bit to the left and the lines dissapeared

Now the image on the monitor is even better than before

Thanks for the help and tips on what was needed to be done to fix the issue