Sticky Topcat (HP-97/HP-91) keys

[Dave92F1]

I recently bought a HP-91 on eBay, in great condition except the "0" key was very sticky.

I was going to try to lubricate it, but discovered that a good blast of canned air (from both sides, but without disassembling the keyboard) fixed it 100%.

Probably a speck of dirt in there was making it sticky.

I hope this helps somebody.