HP-67 stuck in scientific (DSP 0) mode

[tribidouille]

Dear members,
Thank you to everybody. I am impressed by the number, diversity and quality of the answers!
To make it short, it is dead, teardrops!
As my post is long, so much to answer, thanks again, I'll use Bold to allow reading faster.

@Moggul: thank you for the http://www.teenix.org link. Very very interesting solution to fix pcb problems and make it alive again.
In addition, (I never use bluetooth but cables). bluetootth is so anachronic that it is a must -IMHO.

@Helix: Good question instead: batteries. I did use an external 25 years old german stabilized power source set to 3.6V. I wanted to test the lovely device prior to renew the battery pac. This power source has been used on lots of electronic devices but: I now slap my forehead: for sure, the HP-67 is too sensible for that. Isn't it?
What a donkey!

(07-18-2020 12:31 AM)Helix Wrote:  ...
Also, dirty contacts under the ON/OFF and PRGM/RUN switches can cause very strange behavior. I had such an experience with a calculator whose PCB was very dirty.
So, try to clean the PCB under the switches, and then put silicon grease, or better dielectric grease:
https://www.hpmuseum.org/forum/thread-13159.html

On/off switch: cleaned, no effect. but: if this switch contact quality is important, I'd surely also mention the golden blade making contact between the two (positive) pins of the battery plug (on the calc. side). It seems to me that this blade is connecting these pins when the charger is unplugged and disconnecting by being pushed away when the charger is connected. As power from the battery runs through here, it is also important to have a good contact, I'd say. Or?
The Panamatik new ACT solution is also interesting but solves less potential problems as the pcb is not replaced if I correctly understood. I also like card reader too much, even more than an USB stick!

@teenix: all contacts cleaned. No way.

(07-18-2020 10:25 AM)Maximilian Hohmann Wrote:  ...
What I meant is that pressing DSP followed by a number key will set the number of decimal places. Pressing DSP after pressing "g" will put the display in Scientific notation mode.
So both faults (?) seem to be connected to the DSP key.
...

Sorry, I messed up. But no, the key is ok.

(07-18-2020 10:25 AM)Maximilian Hohmann Wrote:  ...
And regarding AndiGer's suggestion to set the display mode by a small program this is what you could try:

1. Place the "W/PRGM - RUN" switch to "W/PRGM"
2. Enter the following sequence of keystrokes:
f LBL A
f FIX
DSP 2
h RTN
f LBL B
g SCI
DSP 0
h RTN
3. Place the "W/PRGM - RUN" switch to "RUN"

Pressing the "A" key should put your calculator into the normal operating mode displaying "0.00"
Pressing the "B" key should put your calculator into the mode of your machine displaying "0.__________00"

Good luck
Max

Not working (tryed twice to avoid typos)
But Wow! This is magic. I used to practice basic, C++, python, HP-41C that I don't remember the syntax... but this is just beautiful. Thank you even if it failed (because of my 67 failure, no your code).

Now, two side questions. I need a pretext not to leave, so if one has too much time :--):
-I read "Woodstock Series" here and there. What is it exactly?
-How do you solve the HP-&/ sticker problem to access the screws? Do you gently unstick it with a part of cutter blade or do you make a clean hole into it?