HP-21 keybord malfunction


I got a used HP-21 where the 4 key almost results in 7 or nothing or sets the system in a obstructed state. It's quite impossible to enter 4444. Is there a chance to repair it? For schlemiel ones like me too??


BTW: All who waited for mail from me the last 6 month -- sorry! I had/still have to care for my health.


hi mike,

try this, it has worked for me on several woodstocks. take the machine apart and separate the circit boards. you don't need to dismantle the keyboard. the idea is co tony duell.

find a fine wire brush and poke it into the holes in the back of the keyboard circuit. if you look closely you might see some green inside the holes. ive seen this on several and its small amounts of corroded copper and possibly the problem.

try pressing the key at the same time as working the brush. this squeezes the contact against it and can help as long as you're not too violent.

hope this helps,

Edited: 5 Dec 2005, 10:16 a.m.


TNX a lot! I'll try it.



Hello Mike!

Did you succeed in fixing your Hp-21 ?


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