HELP!!!! My 48SX won't turn on!

[l***@gmail.com]

OK, folks...

In case this helps anyone else.

22 year after this post, it STILL is relevant!

My junior is using the same calc I used in high school. HP 48SX.
JUST today we needed to change the batteries. I don't remember changing them at any time in the past 20 years.
Well, the calc wouldn't turn back on. I was about to mourn a lost old friend.
Found this advice about reversing the batteries for a few seconds...

My old friend is resurrected!

Thanks so much, internet.
+ Loretta

Subject: HELP!!!! My 48SX won't turn on!
Date: 24 Oct 1994 22:25:10 GMT
I have a 48SX and recently, it completely stopped working. I can't even get a
rseponse when I turn the thing on... I have no idea how this happened and it
happened long enough ago that I cannot remember the symptoms it gave when it
died. Please help!
-------------------------------------------------------------------------------
The Alchemist Anthony Chavez
ftp: ftp.xmission.com:/pub/users/alchemy/ CompuSci Technology Major (AS)
-------------------------------------------------------------------------------

take the batteries out, put them back in BACKWARDS for a few seconds, then put
them back in the correct way. This seems to reset something (unknown, but
something). I have gotten several hp's to work again doing this, even when
the reset button failed. This will reset your memory as well, but if its the
difference between a working and non working calc, what do you have to loose?
- Blair

[paul]

Try ON-C, ON-A-F, etc. If those don't work, then try hitting that reset
button which is underneath one of the small rubber feet on the underside of
the calculator.

Why is it, ON-A-F is recommended before the button?

Ok, I tried ON-C, ON-A-F and punching the reset button under the footpad. None
of these worked... HELP!!!!!!!!!!!!!
-------------------------------------------------------------------------------
The Alchemist Anthony Chavez
ftp: ftp.xmission.com:/pub/users/alchemy/ CompuSci Technology Major (AS)
-------------------------------------------------------------------------------

[warning this is a last resort method only]

i once stuffed up my HP48g so bad that none of the usual methods
already described worked, so i rang my local HP fixit dudes in melbourne
here in Aust. they said take the batteries out & using a straightened paperclip touch diagonal terminals (2 battery contacts furthest apart)
& lo & behold when i but the batteries back it worked.

i would of course try every other solution before this drastic method.

[p***@gmail.com]

: >
: >I have a 48SX and recently, it completely stopped working. I can't even get a
: >rseponse when I turn the thing on... I have no idea how this happened and it
: >happened long enough ago that I cannot remember the symptoms it gave when it
: >died. Please help!
: Sorry, I should have mentioned: I tried installing fresh batteries too...
: Fortunately, I have a 48GX that I can use in reserve, but I'd love to get my
: older SX to work again!
Try ON-C, ON-A-F, etc. If those don't work, then try hitting that reset
button which is underneath one of the small rubber feet on the underside of
the calculator.
--
Eric Crampton | -Marcus Aurelius

I kept stored the 48sx without batteries for years and it did not start when putting in the new batteries. I tried any reset procedure found in the internet with no results.

What worked for me was: putting only one battery (the top most one) and leave it for several days (maybe one week). All of a sudden, when I tried to add the other two batteries ... it went alive.

I don't know why ... but it worked.

[o***@mindspring.com]

Post by p***@gmail.com

: >
: >I have a 48SX and recently, it completely stopped working. I can't even get a
: >rseponse when I turn the thing on... I have no idea how this happened and it
: >happened long enough ago that I cannot remember the symptoms it gave when it
: >died. Please help!
: Sorry, I should have mentioned: I tried installing fresh batteries too...
: Fortunately, I have a 48GX that I can use in reserve, but I'd love to get my
: older SX to work again!
Try ON-C, ON-A-F, etc. If those don't work, then try hitting that reset
button which is underneath one of the small rubber feet on the underside of
the calculator.
--
Eric Crampton | -Marcus Aurelius

I kept stored the 48sx without batteries for years and it did not start when putting in the new batteries. I tried any reset procedure found in the internet with no results.
What worked for me was: putting only one battery (the top most one) and leave it for several days (maybe one week). All of a sudden, when I tried to add the other two batteries ... it went alive.
I don't know why ... but it worked.

HP calcs have a small amount of onboard energy storage, to maintain the clock and such while the batteries were being changed. This can keep the processor alive, and if it's in a stuck state it might not restart with new batteries. The solution for certain older calculators (I don't remember which) was to install (all) batteries backwards for a few days. This will quickly leak away the stored energy. Then when the batteries are replaced, it's a clean start and usually succeeds. I'm surprised that adding just one battery worked, but the currents are tiny and maybe there was enough leakage to do the trick.