HP-25 turns itself off

Ok, here's a strange one. I was playing around with my HP-25 the other day making sure all the buttons work. I went through each number and pressed it over and over until it filled the display. When I got to the number 7, I pressed it 5 times and the calculator turned off. It turned back on again after sliding the switch to off and then on. Here's some of the patterns that turn the unit off.


You get the idea. Any help would be appreciated.


I would like to say that entering five '7's in a sequence or over the 10s display is the "secret off code" for the HP 25 but I can't!

Sounds like a memory and display problem. The x register is a memory. Did any of the other keys when entered five times in a row or any sequence of five presses over the 10s display cause a similar fault. Also try:

388885 ENTER 5 /

this should develop 77777,

Does it turn off when it generates the 5 sevens.

Cheers, Geoff

Possibly Related Threads…
Thread Author Replies Views Last Post
  Strange HP 25 Problem (Repair) Onur Ilkorur 5 2,626 12-06-2013, 05:13 PM
Last Post: Onur Ilkorur
  HP-25 Wayne Selway 1 1,124 11-22-2013, 12:58 PM
Last Post: Michael de Estrada
  Interesting Base Conversions - Porting a 1975 HP 25 Program to the HP 35S Eddie W. Shore 1 1,237 10-13-2013, 07:49 PM
Last Post: BruceH
  HP-25/25C Potential Matt Agajanian 14 3,872 07-17-2013, 02:57 AM
Last Post: Matt Agajanian
  Recharging original batteries in HP 45, 65 and 25 Michae Altmann 1 1,111 03-05-2013, 12:21 AM
Last Post: DavidShenk
  HP-25 keyboard Brad Barton 5 1,711 02-16-2013, 09:59 PM
Last Post: Brad Barton
  HP 65/25 shout-out in interview with Paul Lutus Egan Ford 3 1,404 12-21-2012, 11:09 PM
Last Post: Mike Morrow
  New HP-25 Emulator for iPad, iPhone, and iPod Namir 5 1,946 05-22-2012, 06:22 AM
Last Post: Mike (Stgt)
  Subroutine tactics for the HP-25 Matt Agajanian 3 1,304 04-19-2012, 05:45 PM
Last Post: Trent Moseley
  HP-25 aj04062 13 3,387 03-30-2012, 03:23 AM
Last Post: Russell Dobson

Forum Jump: