HP 35 Keyboard Malfunction
#1

I just got an early 35 with the BUG and a raised dot on the 5. I was testing it out after getting it going and I noticed the whole row of keys starting with the 1/x key register as different keys. I disassembled and cleaned the keyboard but that did not cure.



Ideas?



I cleaned the keyboard to motherboard contact some but not thoroughly yet.

Thanks!

Edited: 8 Aug 2011, 6:45 a.m. after one or more responses were posted

#2

I'd look for corrosion shorting two of the "row" lines, which could be on the keyboard circuit board or on the logic circuit board. Although if two lines were shorted, then you would expect odd behaviour from two rows of keys. Maybe there is somewhat of a short from the row line to another line causing the problem.

Have you tested for continuity from a keyboard row all the way through to the CPU chip ?

Cheers,
John



Possibly Related Threads...
Thread Author Replies Views Last Post
  HP-97 Printer Malfunction Dan Lewis 17 3,997 11-25-2013, 10:18 AM
Last Post: Thomas Chrapkiewicz
  HP-35 blind buy but buggy! Max Stone 7 2,409 11-11-2013, 05:56 PM
Last Post: Dieter
  Another HP 35 Red Dot on eBay Michael de Estrada 5 1,957 11-09-2013, 03:07 PM
Last Post: aj04062
  HP 35 ... 80 Olivier De Smet 6 1,969 08-29-2013, 07:25 AM
Last Post: Olivier De Smet
  HP 35 Pretty Good Purchase Today! Norman Dziedzic 1 1,158 03-05-2013, 12:52 AM
Last Post: Dan Lewis
  Slightly OT: Remember the extraction of the HP-35 ROM? Frank Boehm (Germany) 1 946 02-06-2013, 05:53 PM
Last Post: aurelio
  magnetic strip malfunction aurelio 7 1,964 01-14-2013, 12:25 AM
Last Post: aurelio
  Silver paint for HP 35 case Anoop Sahal 2 1,131 12-26-2012, 10:17 AM
Last Post: Anoop Sahal
  HP 35 #3? ClausB 5 1,665 12-11-2012, 02:48 AM
Last Post: Maximilian Hohmann
  HP 35 Red Dot page Michael Eckstein 6 1,907 11-05-2012, 03:03 AM
Last Post: Michael Eckstein

Forum Jump: