HP-65 low keys



#9

Hi all,
I have a HP-65 wich is in very good condition except the keys. Mainly at the center of the keyboard, around the "8" key, those keys are very low, I would say almost at the half height. They don't make good contact also. I've open the calculator already and cleaned the keyboard PCB using a wet contact cleaner spray and blowing it with an air spray too, which improved the electrical contact but the keys are still down. How could I solve this problem (if there is a solution...)?
Thanks in advance for any suggestion!
Luis


#10

Hi Luis, It sounds like it could be one of the following problems: 1. Keypad pcb is warped. 2. The plastic insert that goes directly over the keys is not properly seated. 3. One or more screws that retain the black plastic piece that inserts over the keyboard pcb are stripped out. My guess is that it is #2.


#11

I have seen quite a few HP65's with the same problem. Don't know the cause though. I don't think it is any of Erik's 1/2/3 suggestions. I have not worked on any that had the problem, but suggested the same things to others that have... they didn't help.


#12

Another common problem I forgot to mention is that the spring part of the key pad may have broken. You can usually fix these by soldering in a replacement from another parts machine.


#13

Again, a no go from past experience. The machines that I was familiar with had reasonable clickage.

#14

Yes, I guess that's the failure. I think the spring plate for many keys (maybe the most used ones) are weak and they aren't strong enough to rise them back. Any idea to make it strong again? What about decrease the clearance between the spring plate and the keys installing some kind of spacer behind the keyboard PCB?


#15

Luis
Is the spring plate broken? If so, it needs to be replaced.


#16

Hi Erik. No, it's not. I still guess the problem is because the spring plate keypad are weak due to its usage.
Luis


Possibly Related Threads...
Thread Author Replies Views Last Post
  Broken keys on HP Prime? Tarcisi C 0 313 12-10-2013, 05:59 PM
Last Post: Tarcisi C
  HP 50g switching two keys in the user keyboard Sean Freeman 9 894 12-05-2013, 11:44 AM
Last Post: Mark Puscas
  HP-65 short circuit Ignacio Sánchez 2 389 10-22-2013, 08:27 AM
Last Post: Ignacio Sánchez Reig
  [HP-Prime] off-center [0], ... [9] num keys CompSystems 1 320 10-18-2013, 10:44 PM
Last Post: Han
  HP Prime - Home and CAS keys BruceH 0 232 10-15-2013, 07:19 PM
Last Post: BruceH
  Very low Price of HP Prime? Harold A Climer 14 1,009 10-10-2013, 01:51 PM
Last Post: Frank Boehm (Germany)
  HP-65 Video Tapes - Anyone have a Copy? Bill (Smithville, NJ) 3 516 10-09-2013, 07:40 PM
Last Post: Paul Berger (Canada)
  Using your HP-65 as a clock! Don Shepherd 24 1,550 10-08-2013, 11:53 AM
Last Post: Don Shepherd
  HP Prime Tip: Setting Up User Keys Eddie W. Shore 2 383 09-27-2013, 09:53 PM
Last Post: Eddie W. Shore
  Low battery slow mode Marcel Samek 4 432 09-18-2013, 02:02 PM
Last Post: Harald

Forum Jump: