Hello again,
It's been several months now and the keyboard gave up again. I had fixed it by repairing the wire last time, and it frayed again so i had to repair it again.
This time i was determined to at least try something different. Ok, so it went 6 or more months without needing repair, but this time i wanted to try something new.
I had an old defunct mouse with a really nice USB cable with special types of internal wires and a very flexible silicone outer cable jacket as this was a good quality gaming mouse. I thought that would make a really nice keyboard cable, so i removed it from the mouse body.
Now once i got past the break in the wire (again) i was able to use the old cable (very stiff outer jacket which kept cracking) just to make sure the keyboard still functioned ok. It was ok, so after testing the old mouse cable i connected it to the keyboard. Unfortunately, on plugging it into the USB port, the system rejected the keyboard and so it would not auto install or be recognized. Measuring the plus 5 volt supply, i saw that it was just too low so the keyboard would not function.
The problem was that the original mouse did not draw much current so the specialized internal wires (which were very small diameter and wound to allow flex without breakage) were dropping too much voltage as the keyboard has a lot of functions on it including another USB port so it demands a lot more current, which of course pulls the voltage down at the keyboard end of the cable. So i had to scrap that idea.
Plan B (which was plan A at one point anyway) was to connect a USB female connector to the keyboard wires, and then plug in an ordinary A/B USB cable (used on printers and other stuff) and that way if the cable became faulty again it would just be a matter of grabbing another cable and plugging it in and that would be that.
So after connecting the B type female USB connector to the wiring of the keyboard, it was plugged in and tested and all turned out well this time. So now there is a B USB connector on the keyboard so the keyboard itself has NO cable to break. If the cable does break now, it just needs replacing by unplugging the old one and plugging in the new one.
It wasnt quite a simple as it sounds however to install a connector like this on the keyboard. I didnt want to modify the keyboard too much but still get the connector mounted solidly. Here's where we enter a ton of hot glue
Ok, maybe not a ton, but almost 3 cubic inches of hot glue (whatever that weighs).
The result was a huge blob of hot glue which firmly holds down the wiring and also the connector. It actually took a few hours to get all that hot glue on there, but it was a matter of applying some and then coming back later and applying some more, in order to let it cool between applications.
The starting pic is where the wiring and connector is just tacked down with some dabs of hot glue, that's the pic where you can see the connector clearly. The finish picture is the finished product after 3 cubic inches of hot glue where added in various application layers and that's the one where you cant see the connector very well. Despite how horrid it looks, it can not be seen normally because it's all on the bottom of the keyboard.
I hope you've enjoyed this little story and gained some insight about repairing keyboard wires. And thanks for all the ideas from everyone here.