Print Screen/Alt Screen Observation

[AKIMbO]

I have a Northgate Omnikey 101...and the print screen button works maybe 1 out 3 times if I spam the print screen button.  However, if I spam alt+print screen it registers every single time (no matter how fast I spam the key).  Am I missing something.  Is there an odd quirk with some select old boards?

[calavera]

2KRO limitation?

[AKIMbO]

2KRO limitation?

I don't think so?  Spamming prnt scrn by itself is when the key only registers half of the time.  Alt+prnt screen it registers everytime.

[mushupork]

By "spam" do you mean pound repeatedly?  Maybe it is pressure related? A normal press does not work but pressing alt + print screen causes you to apply a different touch to the print screen button - one that registers?

[rootwyrm]

Ah, I know this symptom. I'd bet it's most likely a bad switch or bad connection. Adding the Alt key changes the voltage enough to get it to register, but it's not getting enough signal alone. Sadly, I have no idea how to tell whether it's switch or connection or how to repair it.

I would presume our resident Northgate repair guru can shed more light on it. (And probably fix it for you as well.)

[berserkfan]

I have noticed this problem on an old keyboard of mine, where a T key may work but not a combination of keys shift T. But shift-everything else works. Alt-T also works.

It was a rubber dome/ membrane (can't tell the dif) but it puzzles me because how can the membrane be warped/ damaged such that only one combination fails to work. (It has nothing with the keys around T, for instance, which were unaffected and shoudl be affected in a damaged membrane)