Circa 1973
HP-45
Worked great for about 9 years...
Can’t help you but I do remember reverse polish notation!
In college I used my HP allot for Statistics.
My HP-25 got me through Calculus in 1976-1978.
Consider buying an iPhone instead, which will not only do RPN in a calc app, it will link to your computer so you will never lose your information if the on-off switch dies.
As for the rest, my iPhone tells me that you can find HP48 repair information at http://www.hpcalc.org/hp48/docs/opening/
My 48GX is slowly dying.
You might resurrect yours for awhile by pressing below the screen in the middle of the row. I am not kidding.
Then the ON/OFF button will work.
There is a short in your calculator.
Soon the functions along the right side will start failing.
It is kind of like watching an old friend die of cancer.... Not really but it sure sucks to have your calculator die. RPN with multiple stacks is the only way to go.
Tear the button off of the offending switch.
The keypad is a bunch of switches.
Figure a way to conduct electricity through that switch.
It may take a simple press of the underlying bubble switch or a metal contact (jewelers screwdriver) to let the electrons flow from the pull to the throw of the switch.
HP still makes RPN calculators. I had one that carried me thru college all the way to a BSEE. I don’t recall the model #. I have an HP 12C that I bought in about 1985, and I believe it is still running on the original batteries. They still make the 12C, and it still costs $70.00.
If you buy an iPhone, there are many apps that effectively mimic the HP-48 almost perfectly. They range between $4-$14 I think
True to its name an RPN calculator requires you to start with the answer and work backwards.
Think ‘Jeopardy’.
:)
Had one, hated it.
I paid $289 (one month’s rent) for my 48SX in 1991. It doesn’t get used daily any more, just special occasions.
I have the addy of a website that repairs HPs. I dont have it here, but I will forward it home tomorrow and get it for you. The website was forwarded to a bunch of land surveyors (like me) in case our calculators break down. I will let you know...JFK
I’ve had an HP-15C for years and love it. Personally, I just can’t use a non-RPN calculator anymore. The best part about owning an RPN calculator is enjoying the confusion of others who are not RPN-inclined who ask to borrow it.
I’ve taken several HP calculators apart nd I can tell you that spraying anything in the keypad isn’t going to do any good.
Under the keypad is a thin sheet of bubbled plastic. Each bubble corresponds to one of the keys. The under side of the bubble has an even thinner coat of some sort of conductor. When you press on a key it pushes down on the bubble which makes the conductor contact a couple of points on a circuit-board which tells the processor what to do.
Your calculator needs a new plastic bubble sheet and they don’t make ‘em any more. I’d suggest you hit the pawn shops or Ebay for a whole new (to you) calculator.
There is still a thriving market for RPN calculators. Show me an engineer, any engineer, and I’ll show you someone who prefers RPN. The 48 is probably shot. You got your money’s worth out of it.
I have an HP-30 and an old Melcor 400 around here somewhere. Both work fine as far as I know. Get a 50 while you can.
http://en.wikipedia.org/wiki/HP-50#HP_50g
Why not get what you really want. Type HP48G into eBay’s search. There’s actually one new one, still sealed in original package, Buy it Now for $229 (says manual is in Spanish, so perhaps they were on the market longer in some Spanish speaking countries than here). Also 4 used ones, including one with a $79 Buy it Now option (from the same seller as the new one). Another poster noted Amazon. I tend to prefer eBay, due to more detailed feedback and seller discipline systems, but if it’s cheap enough Amazon’s definitely worth a try too.
Or you could just get an iPhone.
