HP 48GX ON key


Hi, I have a HP 48GX that helped me throw collage so you must have an idea how please I’m with this calculator. For several reasons I had to put it away for a couple of years and now that I need it I found that my ON/CANCEL key isn’t working. I have already try the key test and failed. The only way I can make it work is If I apply a lot of pressure and in some times work and others doesn’t. I leave in Mexico and HP had told me that they do not have services for calculators. I believe that if I open it and clean the pad the problem is going to be solve, but… I don’t know how to open it or if it’s a good idea. Can some one help me. GRACIAS!


Good afternoon Marco. Have you tried to adjust contrast on calculator? Maybe it reset itself when sitting so long and need to adjust contrast. I believe I remember reading that if you turn on and then hold ON and + (plus key) it make contrast darker, and ON and - (minus key) it make it lighter.

Also, stupid question, but have you tried new battery? Does the ((*)) stay lit on the display?



Its not the contrast, actually is in excellent setting (you are correct ON + plus key it make it darker and the other way around). The problem is that some times it works fine the button (ON/CACEL) and some time it doesn’t respond at all. I haven’t figured it out if a lot of pressure makes or not a difference. Batteries are new and the clac except this problem is working fine. Thanks for your reply.


Try gently pressing on the faceplate just above the "F" key, and then press "ON". If this makes it work, then do a search of the Archives here to learn more about it.





It doesn’t make any differences. Thanks!


Hello Marco,
have a look at this thread too...



Prego Massimo,

It was very helpful, know I have to find courage to open my HP. I will let you know how did it went.


Ciao Marco,
actually you don't have to open it up: just check if the metal bezel around the ON key is loose or bent so that it stucks the key down.


Edited: 10 Aug 2007, 1:19 p.m.

Possibly Related Threads...
Thread Author Replies Views Last Post
  HP Prime - EEX/X/Toolbox-key suggestions bluesun08 2 1,258 11-07-2013, 06:15 PM
Last Post: bluesun08
  HP PRIME : strange behavior when trying user key capability Damien 12 3,237 11-03-2013, 11:02 AM
Last Post: Joe Horn
  HP PRIME: How to use [a b/c] key from a program Joseph Ec 4 1,562 10-29-2013, 06:18 PM
Last Post: Joseph Ec
  Roll-down key in HP-15C Steve Ross 6 1,875 10-15-2013, 04:12 AM
Last Post: Nick_S
  HP-15 LE Key repair question Namir 2 1,211 06-10-2013, 10:42 PM
Last Post: Namir
  HP calculators: origin of prefix key labels f and g M Habl 9 2,285 11-21-2012, 08:29 PM
Last Post: Gerson W. Barbosa
  HP Key Notes Programmes? Michael Lopez 0 799 07-02-2012, 09:26 AM
Last Post: Michael Lopez
  HP-97 Key Contact Repair Adventure LHH 0 834 06-09-2012, 05:26 PM
Last Post: LHH
  HP 9826A key switches David Ramsey 3 1,103 01-04-2012, 07:29 PM
Last Post: David Ramsey
  HP-15LE: Anybody else see double key registrations? BobVA 5 1,440 11-13-2011, 06:48 AM
Last Post: Jan

Forum Jump: