Question for HP45 owners re. scientific mode

[dos]

I've wanted a calculator from the first series for a while, I took a gamble on this "untested" 45 on ebay for 40 bucks the other day (it came with no battery or charger):



It's in great shape and seems to work nearly perfectly but sometimes it won't switch to scientific mode, or only will if I enter the entire key combination (shift, sci, #) very rapidly. The unshifted fix button always works, and all other shifted functions are perfectly normal. Just wondering if this is a quirk of these models or if there's something weird going on.

[BobVA]

Nice find!

When you try to put it in into scientific mode does it instead go into the fixed mode at the same number of decimals? That is, if you try "shift SCI 6" does the result look like you did "FIX 6" ?

If so, perhaps the "FIX" key is dirty and is generating some key bounce when pressed.

The sequence "shift FIX FIX" is the same as just pressing "FIX", so a key bounce from the "FIX" key will effectively cancel shift key (and consequently the "SCI" instruction).

[dos]

(06-12-2017 03:15 PM)BobVA Wrote:  Nice find!

When you try to put it in into scientific mode does it instead go into the fixed mode at the same number of decimals? That is, if you try "shift SCI 6" does the result look like you did "FIX 6" ?

If so, perhaps the "FIX" key is dirty and is generating some key bounce when pressed.

The sequence "shift FIX FIX" is the same as just pressing "FIX", so a key bounce from the "FIX" key will effectively cancel shift key (and consequently the "SCI" instruction).

Yes that's exactly what happens, good call. I'll try cleaning it when I get home tonight