HP-30b - dead key - repair

[pito]

We converted two WP34s successfully, but after a while the Enter key on one unit stopped clicking. I am thinking about a repair, but cannot find any picture of the assembly. Before opening the keyboard and messing with the key I would be happy to see whether the key to repair is even a feasible exercise.. Is there a picture how the buttons are arranged (the dome, etc)? Thanks!

[Marcus von Cube]

(06-17-2014 07:21 PM)pito Wrote:  We converted two WP34s successfully, but after a while the Enter key on one unit stopped clicking.

You should as well have a look at the overlay. If the label sheet is to close to the cutout the key cannot move freely.

[pito]

(06-17-2014 07:27 PM)Marcus von Cube Wrote:  You should as well have a look at the overlay. If the label sheet is to close to the cutout the key cannot move freely.

Nope, in opposite, the key moves too freely.. So a collapsed dome (if any) or the key jumped off of a kind of plastic "bearing"/suspension (if any), or the bearing broke. Knowing how it is arranged would help..

[walter b]

(06-17-2014 07:21 PM)pito Wrote:  I am thinking about a repair, but cannot find any picture of the assembly. ... Is there a picture how the buttons are arranged (the dome, etc)?

IIRC, there were such photos on the forum antiquum when the HP-30b was new. Searching the forum archives may help.

d:-)

[jebem]

You may like to browse this thread to post #20:
http://www.hpmuseum.org/forum/thread-989.html

Basicly some keyboards show the reported issues, and some folks have managed to fix them, but it is not a nice work to do, as the assembly was not designed to be disassembled in a orderly fashion. You need to break the plastic rivets to get access to the offending plastic keys and then to try to rebuild then with some glue.
I followed another root and have just ordered another 30B. It was so much easier

[pito]

(06-18-2014 05:30 AM)jebem Wrote:  You may like to browse this thread to post #20:
http://www.hpmuseum.org/forum/thread-989.html

Thanks! A pity Shawn did not shot a picture of the keyboard's internals

[Shawn Gibson]

Pito,
If the key is moving too freely, I would suspect the pin ( about 1mm diam.) under the key that presses against the dome is damaged. Now I also wish that I had taken some pictures. If I do another one, I will get some photos and post them for the group.

Best Regards,
Shawn

[Jeff O.]

(06-18-2014 10:42 AM)pito Wrote:  Thanks! A pity Shawn did not shot a picture of the keyboard's internals

Does this help?

[Shawn Gibson]

Jeff,
The one piece that we need to look at is not shown. We would like to see the back side of the keys with the molded carrier. The carrier also functions as the hinge for the keys.

Thanks
Shawn

[pito]

(06-18-2014 12:49 PM)Jeff O. Wrote:  Does this help?

Thanks! Provided it is a fresh picture of 30b - would it be possible to make a picture of the single pcb dome/contact (?) and a detail of a molded key assembly from the bottom?
We decided to work with the loose key until the next one dies - then we will open the stuff.

I plan to drill a conical hole (with the tip of a 2-3mm dia drill bit) into the holes which fix the plastic rivets - then I will mold the rivets into. It may fix the stuff even better than the epoxy.

[Jeff O.]

(06-18-2014 06:17 PM)Shawn Gibson Wrote:  Jeff,
The one piece that we need to look at is not shown. We would like to see the back side of the keys with the molded carrier. The carrier also functions as the hinge for the keys.

Thanks
Shawn

   

[Jeff O.]

(06-18-2014 06:18 PM)pito Wrote:  would it be possible to make a picture of the single pcb dome/contact (?)

   

[Shawn Gibson]

Jeff, Thanks for the picture shows the pins nicely.

Pito, The key that is "loose" probably has it's pin bent or possibly broken off. Of the 3 calcs that I fixed, the pins were just bent. I straightend ( and weakend ) them. Then I used an epoxy called JB weld to re-enforce the pin. So far, the repair has worked great. If the pin is broken, perhaps you can find or make some kind of non-conductive replacement pin. You really don't have much to lose by trying.

Best Regards,
Shawn

[pito]

Jeff - fantastic pictures! Thanks! Now we see how it is done..
I must admit the keyboard is not the cheapest design.. Metallic domes..
On the other hand I would fire the designer who created such thin/slim/feint pins pushing into the dome. They can bend/broke or penetrate the dome. Grrrh..
PS: it seems the + pin is already bent on the picture..

[pito]

(06-19-2014 03:47 PM)Shawn Gibson Wrote:  ..I straightend ( and weakend ) them. Then I used an epoxy called JB weld to re-enforce the pin..

I can imagine to strengthen the bended pin with a small dia plastic tube put onto the pin.. Even to make a 1-2mm long diagonal slot into the bottom of the tube such it fixes the tube against the central rib.. And to fill the tube with epoxy..
For people who are hammering the keys I would advice to apply that to all the pins in advance..

[pito]

(06-19-2014 04:39 PM)pito Wrote:  

(06-19-2014 03:47 PM)Shawn Gibson Wrote:  ..I straightend ( and weakend ) them. Then I used an epoxy called JB weld to re-enforce the pin..

I can imagine to strengthen the bended pin with ..

Encouraged we removed the heads of the plastic rivets with 4mm dia drill bit (wood-boring brad point drill bit). The Enter pin was bent, after repair it has been reenforced with epoxy. See the pictures.
The keyboard has been clearly designed for planned obsolescence..

[jebem]

(06-20-2014 04:53 PM)pito Wrote:  Encouraged we removed the heads of the plastic rivets with 4mm dia drill bit (wood-boring brad point drill bit). The Enter pin was bent, after repair it has been reenforced with epoxy. See the pictures.
The keyboard has been clearly designed for planned obsolescence..

Excellent team work. Thank you all for for sharing.
Pito, did you use epoxy to fix the plastic rivets? Did it wok fine?

[pito]

(06-20-2014 06:03 PM)jebem Wrote:  Pito, did you use epoxy to fix the plastic rivets? Did it wok fine?

Yes we did it with a drop of epoxy on the rivet's heads (14 rivets there), till now it works
PS: When you have got the keyboard opened, do re-enforce all the pins with the epoxy, it may prolong the life of the keyboard..