I have a Fentek KBMCK142 programmable keyboard at work, and one of the keys is failing.

The minus (or hyphen) key on the numeric keypad works intermittantly. When entering a column of numbers into a spreadsheet, sometimes negative numbers get entered as positive. This is a less than desirable result.

The keyboard was expensive, ~$160, and is no longer available. I have located a replacement (different model but workable) for $200, but it is back ordered and I have to have it within the next 5 days.

Is there any magic bullet that can make that minus key work more reliably?

tanstaafl.

It might just need to be cleaned. If it's a membrane keyboard, try taking it apart and cleaning the circuit-board contact for the minus key with a pencil eraser. Most keyboards are not terribly mechanically complex, so that shouldn't require a degree in engineering.

I've also had success in the past with cleaning keyboards by putting them in the dishwasher. Just make sure you don't have the heated dry cycle on.

You could also get a USB numeric keypad, like this cheap one or this, probably higher quality, one.

When I was finding those products. I came across this. Very clever.

I repaired a lot of IBM 101 keyboards in the O'l days. Most were killed by soda pop.

Once apart an eraser works well to clean the contacts as well as washing the individual parts and drying them right away and thoroughly.

The IBM keyboards had a plastic film that acted as a circuit board. I got some liquid conductive paste somewhere that I just painted on the film and that would fix open circuit issues when the film got cracks in the runners.