Dead key on 35s

[Marcio]

Tugdual has a 15LE. He just doesn't like having to decipher keycodes. I don't mind them. The downside for me is that the 15C will allow two different programs have the same label, which can be misleading if you don't remember where things are or what they do.

I know. Sacrilege!

[Jlouis]

(03-12-2016 11:12 PM)Marcio Wrote:  Tugdual has a 15LE. He just doesn't like having to decipher keycodes. I don't mind them. The downside for me is that the 15C will allow two different programs have the same label, which can be misleading if you don't remember where things are or what they do.

I know. Sacrilege!

Sorry, I didn't know that.

As for remember the programs, I use a little piece of paper inside the slipe case with labels and short description of the programs.

I know this is awful, but it has been working for me, as I barely remember wich day I was born.

[Marcio]

Tugdual,

Did you fix the bad key on the 35s?

[Tugdual]

(03-16-2016 08:17 PM)Marcio Wrote:  Tugdual,

Did you fix the bad key on the 35s?

Nope, I think Maximilian made a point and also Jebem kinda discouraged me from attempting anything. If it was a simple thing such as open, clean I would have tried but breaking plastic rivets to fix pins is above my available time/skills.

I still have an open question: what are the residues, what do they look like? Is it dust or particles?

[Thomas Radtke]

(03-17-2016 06:17 AM)Tugdual Wrote:  I still have an open question: what are the residues, what do they look like? Is it dust or particles?

In case of the 15C LE it were particles. In one of those threads discussing this issue, someone took pictures and posted a link. Can't find it right now, but I have seen them myself.

[Jeff O.]

(03-17-2016 06:17 AM)Tugdual Wrote:  

(03-16-2016 08:17 PM)Marcio Wrote:  Tugdual,

Did you fix the bad key on the 35s?

Nope, I think Maximilian made a point and also Jebem kinda discouraged me from attempting anything. If it was a simple thing such as open, clean I would have tried but breaking plastic rivets to fix pins is above my available time/skills.

You must certainly be the judge of what you are comfortable doing, but I would not be too scared by the prospect of removing the plastic rivets. They are not that difficult to deal with, and there are screws that will hold things together without the rivets. Paraphrasing from a post of mine at the old Forum regarding disassembly of a 35s:

Quote:It certainly appeared that the PCB was held in by those small screws (25 of them), so I removed them all. Gentle prying on the edges of the PCB did not yield any movement. Close inspection revealed that the posts into which the screws were screwed were mushroomed over at the top, just like the heat stakes in other HP calculators. Taking a cue from the tips for disassembling those calculators, I attempted to trim off just the mushroomed-over portions of the posts, i.e. leave the center part of the post sticking through. I was unable to trim them cleanly enough to free up the PCB, so I just trimmed the posts off flush with PCB, and with a little gently prying, was finally able to free up the PCB. (I then realized that this was likely to be necessary anyway to enable the screws to hold the PCB back in when it is re-installed. Otherwise, the screws would not be able to tighten down against the board to hold it firmly in place.) Once the PCB comes out, next is a thin rubber membrane, then the keys themselves.

There is an adhesive sheet of plastic on the keyboard side of the PCB, under which are the metal domes that are the key contacts. If your problem is contamination under one of the contacts, you must peel that sheet off to clean. I have no experience peeling off or re-attaching that sheet.

[renif]

(03-17-2016 06:17 AM)Tugdual Wrote:  

(03-16-2016 08:17 PM)Marcio Wrote:  Tugdual,

Did you fix the bad key on the 35s?

Nope, I think Maximilian made a point and also Jebem kinda discouraged me from attempting anything. If it was a simple thing such as open, clean I would have tried but breaking plastic rivets to fix pins is above my available time/skills.

I still have an open question: what are the residues, what do they look like? Is it dust or particles?

It is totally understandable that you do not want to invest much effort and time in a relatively cheap calculator of current production. On the other hand, in such a case one can still try a quick (and dirty) approach. The old forum is full of tricks, showing how to cure keys that don't register (e.g. http://www.hpmuseum.org/cgi-sys/cgiwrap/...869#217869). Many use Deoxit Gold or comparable product. Without opening the calculator, of course you are restricted to applying this cleaning solvent not directly to the appropriate contact surface but to pour it carefully from the outside into the key mechanism. With some cleaning solvent already at hand, the cost of material and time is small. I'd try to apply some of it from the side of the key front. If you manage to let it flow all the way to the contact surface, then pushing the key repeatedly should help removing residues and restoring the key function. It once worked for one of my HP-41C, which I didn't want to open either. Of course, one certainly should not try to spray directly onto the key as the painted keyboard labeling may dissolve...

Good luck!

[Gerald H]

My experience is 3 of 27 new 35Ss had defective keyboards.

In use since 2008 the remaining 24 function as well as when new.