1990 Haas VF1 video monitor fuzz

[ChuckMTB]

I picked up a 1990 VF1 and it has an newer monitor installed.
It has fuzz and I have read that I need to change the cable...
Does anyone know where I can get it or a part number?

thanks

[Wizzard of H]

I'm not sure what you mean by monitor has fuzz.
Do you mean the screen is fuzzy?
Is it out of focus?
This is rarely caused by a cable.
The CRTs get old and images get poor.
Replacements from third party or from Haas are available.
If working on your own, it is the old IBM Monochrome MDA standard.

Also what do you mean by newer monitor.
Is that different than what the machine had new?

[ChuckMTB]

I did not describe the problem very well....
I was told that the machine has a "newer monitor"
It is a monochrome with a haas on the bezel.
When I type I can not read the text. It is stretched and staggered up the screen.
It will also get a faint snow that moves across the whole screen on occasion.
One person I know said it might not be shielded??

hope that helps...

[Machineit]

The monitor/CRT itself does not cause these issues. If the letter and numbers were just blurry and hard to read it may have been because the CRT had been burned in, meaning it was just worn out.

The issues you are seeing come from a failing video board or from misadjustment of the monitor controls. These units are just like an old TV set and you can adjust the horizontal/vertical/focus etc..

The controls are in the rear of the monitor, accessible by removing the rear cover on the pendent. It has been a long time since I replaced my CRT, but I think the pots were labeled as to what they were. I know that even with a brand new CRT I had to adjust it after replacing it.

If you have someone try to adjust it and it will not adjust, then it may be the video card/board.

The monitor on my 96 VF-2 is burned in but readable and I can't afford to replace it quite yet. Maybe in a few months.

Mike

[Wizzard of H]

One more thing to try.
Parameter 57 has a bit in it called "neg sync".
Some machines needed this on; some need it off.

[Ydna]

We have a '93 VF that had its monitor replaced last year, and now experiences some "snow" when the spindle is running. It's obviously noise/feedback of some sort. The tech said he'd seen this before but was unaware of a fix for it. That said I've read things here on cnczone about a different monitor cable or something, it's certainly plausible.

YouTube - VF1 monitor fuzz - When the spindle starts up, the text on screen gets a tad more dim, and little pixels randomly flash the regular brightness. You can kinda see it in that video.

Minor irritation since we don't use the machine as much as the newer ones. We've just been living with it ever since the ole tube died.

[ChuckMTB]

I have been really sick and slow to get back to the machine. (Chemo)
Thanks for the responses.
It seems I have two different issues.
The "snow" does show up when the spindle runs. That I can live with.

I have attached an image of the other problem,that would have been the easiest way to describe it to start with! (the one that I need to solve).
The hash marks that run up the left side of the screen is the current line of text that I am imputing.
I tried to adjust the monitor from the back but none of the adjustments solved the one line of cut up text.
I will try the parameter 57 "neg sync" change today and see if that helps.

[Wizzard of H]

Golly, let me put my "way back hat" on...
Actually the problem is a monitor that is not sync'd in vertical.
There are two possible fixes for this.
The first is phase or sync adjustments on the small pots inside the monitor.
The second is a parameter that selected "NEGative VERTical SYNC".
(It might be called inverted vertical sync.)
It is probably part of parameter 57.
If 0, try 1, etc.