old & rare? HP35:Help needed to repair

[Didier Lachieze]

(01-04-2018 08:17 AM)Dieter Wrote:  Looking at the back label there are two things that catch my eye:

First, the stack diagram at the bottom has the X and Y lines reversed. And in the third (or fourth) column there is an "E" instead of a 3. Are these errors also present in other languages? Or even in later German labels?

Good catch ! Effectively the X and Y lines reversed and “E” instead of 3 in the third (or fourth) column are present in the early Singapore labels for several non-English languages (verified for German, Dutch, Italian, French and Spanish). These issues have been fixed in the second revision of the Singapore labels (German label ref changed from 00035-80013 to 00035-80040).

(01-04-2018 08:17 AM)Dieter Wrote:  Then the instructions seem to suggest that STO does not enable stack lift, just like CLX and ENTER. Is this really true for the 35s?

Yes, if you type: 25 STO 4 , 25 is stored in the memory register, then 4 replaces 25 in the X register.
This is also mentioned in the HP-35 manual:

Quote:MORE MEMORY
Your HP-35 has an additional memory register for storing constants. It is not affected by computations.
However, a keyboard entry or RCL immediately following STO does not raise the stack.

@Ignacio, unfortunately I've no clue on the issue with your HP-35, however you should be able to test your CPU board in an HP-45 to check that it is working correctly. If yes, then you will have to investigate the keyboard/display board of your HP-35 and eventually replace it or the display drivers (as far as I know you should be able to use a board from an HP-45 if you have one available).