I bought two laser desktop 6000 sets and you have NO idea, NO IDEA, how flawed the keyboards and mouses were. The keyboard's spacebar was made of such low quality plastic that during use the tiny hooks that kept in place the metal bar that allows pressing the spacebar from the sides (and not just the center where the keyboard contact really is) kept consuming until they couldn't hold the bar anymore. I tried adding meters of tape everywhere, on the bar to make it thicker so that the hooks could still keep it in place and in the keyboard button to keep the bar in the right position but it didn't help for long: in a couple months both keyboards became useless without ever pressing the bar on the sides.
The mouses instead had such a tiny sensor opening (I don't even think it's sealed) that dirt kept getting in, even the smallest dust grains from the mouse pad could wreak havoc making the mouse unresponsive until it was cleaned with blows and pincers, in the end I had to stop using the mousepad and one of my tables was left with a big stain of it because of the mouse's attrition: the tiny pads under the mouse didn't help at all, they were way too thin and couldn't prevent the entire mouse area from rubbing the table. And that's not all, the wireless receivers kept reporting low signal even when I placed the ugly receiver less than a few centimeters away from the keyboard/mouse.
Many people left bad reviews of that desktop set for the same reasons but sadly, when I bought the sets, I looked the wrong reviews because didn't notice there was a newer revision (2.0) with a completely new and different keyboard that didn't have any of those issues. Also in these days I was moving to another house and had no idea of where the receipts ended so I had to keep those two 79$ dollars paperweights.
Logitech keyboards are made of cheap, maybe cheaper plastic but I never saw one breaking up like this, heck, I still have far cheaper keyboards from the early 90s that I used far more than those and they all still work perfectly.
If I have some spare time I'd make some photos, maybe the other desperate guys looking on the internet for a way to fix that keyboard that end up here will get some hints of how to get it working for a few more weeks, just the time needed to find another set and organize a proper funeral. Yep, seeing expensive high-end hardware failing like this is really that sad.