KTX, Coug, nothing to do with KDX in the USA.
Hi Rick, and welcome to the crazyhouse. Stick around, it's good to see another Aussie here.
I can tell you a little about KTX and their monitors (a good deal of which you will already know, more than likely) but probably very little of practical use to you.
(Bear with me if you already know all this stuff.)
KTX was a "home brand" applied to monitors, modems, and anything else that seemed like a good idea at the time by one-time Australian wholesale Kings of Sleaze, Edge Technology. Edge are bankrupt now, and I don't think one single person has shed a tear. Except for their creditors, of course. But for a good long while through the greater part of the 90s, they were one of the biggest wholesaler/importers in Australia. They were famous for vast sales volumes, low prices and even lower quality. Only thing you could say that was not low-rent about Edge - aside from the salaries of the directors, one presumes - was their service. Edge were one of those companies that believed in the modern efficient business model, and didn't like to waste valuable resources on non-income generating assets like a service department.
Another thing Edge didn't like to waste too much money on was their research and QC department. In consequence, sometimes they buggered up their purchasing so completely that they imported a whole stack of decently made products by accident. At least I presume it was by accident, the idea of Edge actually importing a quality product as a matter of policy strikes me as a little far-fetched.
Anyway, some of their monitors were actually excellent; notably the long-running 15 inch model from about 93 or 94 with the white casing and the little LCD frequency & resolution window at bottom left. I still have one of those and use it in the workshop every day. But Edge bought monitors (and other products) from all and sundry, always relentlessly chasing the lowest possible price, one assumes, and switching manufacturers often. Certainly the quality of their monitors, which had been quite good up until about 1994 or so, deterioriated markedly from then on. Each new model of KTX monitor was crappier than the one previous, and appeared to be from yet another different manufacturer.
I have no idea who was responsible for the thousands upon thousands of fake cache 486 main boards that appeared in Oz about that time, but I shouldn't be in the slightest surprised to find that it was Edge. In fact, I'd take three to one on it.
Anyway, the long and the short of it is that you have three challenges ahead of you. (1) Discover the actual manufacturer of your monitor. It could be almost anyone, but is almost certainly not any of the major names. (2) Extract the information you need from them. (3) Actually fix the monitor.
Sorry that this is no real help to you, but still, it provided an excuse for me to do one of my customary character assasination posts (which I enjoyed) so all is not lost.
Good luck with it!
Tony