I have a Microsoft Ergonomic 4000 keyboard that suffers what most MS keyboards suffer: key bind. When the keyboard was new I could fly over the keys but now if I hit just a little off-center they bind. I've disassembled and cleaned, but that did not help. So I figure that I'd lube them.
Silicon lube did not help, and I'm wary of using graphite (might short out the innards if it gets around) or petroleum-based lube (might eat the plastic). I read online to use Super Lube Dry Film spray which is PTFE-based but it is unavailable where I live. I can get other PTFE lubes but they are expensive (half the price of a keyboard) and I don't know if they will work.
I'd like to repair this keyboard instead of replace it as it is heavily modded. For instance, I cut the silicon domes so that they require less pressure to press. I could take the silicon sheet to the new keyboard, I suppose, but in any case I'd rather keep lubing than buying new keyboards.