Been having problems with a 5 year old keyboard.
The problem here is that the keys are rather hard to press, sticky, and unresponsive. I already did a full keyboard cleaning where I pried off each key and cleaned each key from top to bottom and removed all the gunk and grime that were in and between these keys on the keyboard side.
Only problem is, although this helped my sticky key problem a little bit, I'm noticing that more and more of my keys are just less responsive. They take more force to "push down" so that the computer recognizes I hit a key. Sometimes after I hit a key, it'll be really slow at coming back up, which makes it frustrating for me since I type 80-90 WPM.
After prying the keys off, I noticed the silicon nipple/nubbin that is in each key seems to be very soft to the touch and not very springy. This makes me think that silicone "layer" that's on the bottom side of the keyboard is just worn out from too many button presses. I've had this happen before with game controller buttons, where the buttons stop losing their responsiveness due to overuse. Had to take apart these controllers and wap buttons around so that the buttons I used the most on my gamepad got the "good" little rubber/silicone pad.
Any way to put the spring back into these things or am I out of luck?