The Museum of HP Calculators

HP Forum Archive 13

[ Return to Index | Top of Index ]

request for help with my 48sx on key
Message #1 Posted by db(martinez,california) on 22 Nov 2003, 3:25 p.m.

The on key to my 48sx is not operating in many of it's uses but it works fine for others. The calculator has had a cushy life. I bought it in 91 and it has spent most of its life in an enviornmental case. The on key feels like new. I hope someone has a fix. Here are the main faults and other points:

To turn the calculator on it is necesasary to push and hold another button while pressing the on key.

To turn it off you must take out a battery of a moment because >on does not work.

There is no "continue" because <on doesn't do anything.

ATTN does not function.

It is not possible to darken or lighten the screen using on+ or on-.

It fails the keyboard test and does not beep at the on key.


As i said; it can be turned on with the on key as long as one or more of most of the other keys are pressed and held first. The right cursor does not work for this but the other three do. Most numbers help it turn on but not the 9. It turns on if you press the < then the on but not the other way around and nothing goes with the > key.

The a-f-on reset works.

The tests which are started by pressing the on and one of the top row all start, but as i said, it fails the keyboard test when it gets down to the on key.

Thanks for the help. - d

Re: request for help with my 48sx on key
Message #2 Posted by Victor Koechli on 24 Nov 2003, 11:22 a.m.,
in response to message #1 by db(martinez,california)

The 48 series seems to have a contact problem between the main PCB and the keyboard. There have been several posts about this recently. Supposedly the ON key will work if you press on the metal bezel above (or below?) the C key. If your HP-48SX exhibits that behaviour, only disassembling it could solve it.

Of course you could also have a broken trace somewhere. The consequences would be the same.

Someone else have another idea? Regards, Victor

[ Return to Index | Top of Index ]

Go back to the main exhibit hall