HP-97 Weirdness


I have an HP-97 on my desktop which serves as my daily driver.

Every few months the keys in the 2,5,8 column behave strangely. Rather than entering the digits, they cause Error to print on the paper, cause the display to dim, and generally misbehave.

I was assuming that maybe there's some dust inside it, on the keyboard contacts and should perhaps rebuild it.

However, the weird thing is that if I switch it off for about a month, then when I switch it on again, all is well.

I don't know enough about electronics to diagnose this, but could it be some faulty capacitor, that once discharged results in the unit working correctly again.

Any thoughts as to the cause, and perhaps what you would do to fix it?




Does it happen both on and off the charger?

Possibly Related Threads...
Thread Author Replies Views Last Post
  HP 67, 97, 97+ emulator Olivier De Smet 8 666 11-11-2011, 09:57 AM
Last Post: Israel Otero
  HP 20B Prediction weirdness? Joao S Veiga (Brazil) 22 1,196 05-14-2010, 09:30 PM
Last Post: Vieira, Luiz C. (Brazil)
  HP 35s keyboard weirdness Hiawatha Wheelwright 6 482 01-12-2010, 05:02 AM
Last Post: Bart (UK)
  48G keyboard weirdness Lincoln 5 417 01-10-2010, 03:09 PM
Last Post: Vieira, Luiz C. (Brazil)
  HP41 card reader weirdness Les Wright 6 461 01-28-2007, 05:12 PM
Last Post: plasmoid
  33S: nCr weirdness kc 10 647 05-20-2004, 08:40 PM
Last Post: Eddie Shore
  HP 41CV Weirdness - Sort of Long Wayne Stephens 4 365 05-03-2004, 10:55 AM
Last Post: Diego Diaz
  HP-41CV Keyboard/Behavior Weirdness Paul Brogger 4 339 04-04-2003, 09:30 AM
Last Post: Paul Brogger
  HP 67/97 "Trick" Cards Warning for HP-97 Users Dan M (Vermont, USA) 0 174 09-12-2002, 08:31 AM
Last Post: Dan M (Vermont, USA)
  HP-25 display weirdness Jonas Otter 0 154 06-23-2002, 07:37 AM
Last Post: Jonas Otter

Forum Jump: