Maker Pro
Maker Pro

NOS KDS XF-9I CRT, geometry issues

Scythifuge

Jun 2, 2021
3
Joined
Jun 2, 2021
Messages
3
Greetings,

I hunted down and found a 19" KDS crt PC monitor. I need a CRT monitor for MS-DOS projects and for hardware/software preservation projects, and I have never found an LCD that can display old software and OS properly. I used this KDS for probably less than 20 hours. I was updating Windows 98 and the monitor blanked in and out a few times, and the picture was then fuzzy and distorted. Eventually, it was corrupted and black and white. I connected it to the VGA port on my laptop and was able to get a distorted picture and I tested the various refresh rates.

I then reconnected it to it's PC and the colors are normal. However, it seems that half of the geometry settings in the OSD aren't working at all. If I go into Windows safe mode with low color depth and 640x480 resolution, the picture almost looks normal. However, running it at 800x600 or 1024x768 creates a pincushion effect, as if the sides are pushed all of the way in. The pincushion option in the OSD does nothing at all. I can stretch or shrink screen on the vertical end, though not on the horizontal, and the picture looks overscanned on certain edges, no matter what I do.

This monitor sat unused in a sealed box, perhaps since 2003 or so, so maybe the caps started going bad just from age. It seems that this monitor can be salvaged, as I am getting a picture. I have no idea what the components are in this thing, though I do have a 17 inch KDS and wonder if the part that controls some of the geometry settings is the same as the 19". I know that CRTs are hard to find and finding someone that repairs them is even harder to find, though if anyone has any ideas, they would be greatly appreciated. I spent a chunk of money on this and I desperately need to get it working again.

Many thanks!
Scythifuge
 

PETERDECO

Dec 19, 2019
239
Joined
Dec 19, 2019
Messages
239
Welcome to the forum - although a month ago! I would try spraying all the switches and controls, even the internal pots on the circuit board, with contact cleaner. I don't know where it was stored but I had a perfectly good guitar amp that sat in my cellar for only about a year and I had to spray all the controls to get rid of the crackling and scratchy sound. Video is not immune to the same problem.
 

Scythifuge

Jun 2, 2021
3
Joined
Jun 2, 2021
Messages
3
Welcome to the forum - although a month ago! I would try spraying all the switches and controls, even the internal pots on the circuit board, with contact cleaner. I don't know where it was stored but I had a perfectly good guitar amp that sat in my cellar for only about a year and I had to spray all the controls to get rid of the crackling and scratchy sound. Video is not immune to the same problem.


Thank you for your reply! I truly appreciate it! I found a website from another country where a technician fixed a TV with a very similar issue and he had to replace a capacitor and a poorly soldered diode. People in other forums have suggested to replace the caps on a particular board that controls horizontal picture signals. I think that the monitor was stored in a warehouse or inside of an office building. The monitor was never opened until I got it. I found a technician about an hour and twenty minutes away who is willing to look at it, but I like the idea of opening it up and spraying contact cleaner everywhere. The contacts could have corroded from years of sitting with random temperature and humidity changes, or from the box being moved around over the years. The capacitors could be suffering from cap rot, due to their age and probably from being cheap caps, given that this monitor was probably one of the cheaper 19" monitors back in 2003.

I am going to make or buy a discharge probe and examine every component with a magnifying glass. Because I want to always have a working CRT (unless they make a suitable replacement for CRT tech that displays 4:3 content the way it was originally intended,) I want to learn how to solder and desolder components, safely. Since I made my original post, I acquired two 21" CRT monitors and two 17" monitors, and I have another old Gateway 19" monitor and a little old 13"or 14" monitor, and the 19" and the little monitor have issues, so I can practice on those. But I will look into contact cleaner and open up the KDS to look around before taking it to the tech. It is nice that I found these 21" CRTs (and I can get 4 more of them for cheap,) but they are too big for my retro PC desk set up, with 19" monitors being a sweet spot.
 
Top