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

[BazookaBen]

Looks like what happens with Trinitron computer monitors when the G2 voltage gets out of hand.

[Nodoyuna]

Can it be fixed?

[BazookaBen]

Can it be fixed?

Yeah, it can definitely be fixed. There are a few ways, some more elegant than others.

On Sony VGA Monitors there is a program called WinDAS that you use to adjust this stuff. See if your tube is made by Sony, if so, then there's a chance.

If not, there are other ways to adjust G2 voltage, so just Google them. Make sure include the words "retrace lines" because that's what you're looking at.

[Nodoyuna]

I'll check...

I hope it will be an easy fix, as I don't know nothing about soldering and all...

[BazookaBen]

It could be as simple as turning a potentiometer on the flyback. No need to be intimidated

[maxtherabbit]

I have a trinitron PC CRT with a Sony tube but the chassis is made by KDS - the flyback has the usual focus and screen pots

[mikejmoffitt]

You can maybe just turn down the Screen (G2) control on the flyback, but the fact that it's purple makes me think it's got some bias adjustments to make. Bias doesn't usually "just drift" over time, unless capacitors have worn out (common) or the tube has changed characteristics (common too, but seldom so extreme as to turn the screen so purple!)

[Nodoyuna]

Hi

Tonight i've opened the monitor, I've been able to fix the retrace lines issue

It was the FIRST time I looked to the inside of a tube, so at first I was a bit lost, but finally, I located the SCREEN pot and turned it a little to the left and... the lines were gone!

So now the monitor has even better image than before

Thanks a lot to everybody for the help and the tips about what was needed to be done

[BazookaBen]

Awesome man thanks for the update.

I'll need to do this for some of my Sony PC CRT's, most of them seem to have brightness drift upwards over time.