Post Reply 
HP16C display problems
01-28-2015, 02:53 PM
Post: #1
HP16C display problems
I just brought my old 16C out of retirement. I love the feel of the buttons and working in rpn still feels as good as it did 20 years ago.

However, there are a couple of problems.
  1. the top right segment of the second digit is broken and never activates
  2. the display will briefly flash the other segments and the various program indicators (c, g, f, user, begin, grad, etc) at random times.


So, my questions are:
  1. any thoughts on a diagnosis?
  2. is this repairable or a lost cause?
  3. if it is repairable, where could I get a new display?
  4. if I was careful, could I disassemble and clean the calculator myself or is it a specialist job?


thanks
Find all posts by this user
Quote this message in a reply
01-28-2015, 03:40 PM (This post was last modified: 01-28-2015 03:53 PM by Katie Wasserman.)
Post: #2
RE: HP16C display problems
(01-28-2015 02:53 PM)joes Wrote:  I just brought my old 16C out of retirement. I love the feel of the buttons and working in rpn still feels as good as it did 20 years ago.

However, there are a couple of problems.
  1. the top right segment of the second digit is broken and never activates
  2. the display will briefly flash the other segments and the various program indicators (c, g, f, user, begin, grad, etc) at random times.


So, my questions are:
  1. any thoughts on a diagnosis?
  2. is this repairable or a lost cause?
  3. if it is repairable, where could I get a new display?
  4. if I was careful, could I disassemble and clean the calculator myself or is it a specialist job?

Just one segment being dead indicates that the problem is with the LCD display itself nothing else. You can confirm that it's just one segment by running the standard keyboard/display test <ON> + <divide>. Keep in mind that not all LCD display segments are used in the 16C, but running the keyboard/display test does use all segments.

The only fix for a bad segment is to replace the display. The display is the same as used in all the other Voyagers so finding cheap 12C from the same time period to pull the display from would be the way to go.

If it's more than one segment it might be a bad connection between the LCD panel and the PCB. If so, that's fixable. I'm not sure if the display connection used on the 16C changed over the years of production. Early ones used zebra pressure connection, these days the 12C uses a soldered connection. You can open up your calculator to have a look. (There is a screw under each rubber foot.)

-katie

Visit this user's website Find all posts by this user
Quote this message in a reply
01-28-2015, 05:14 PM
Post: #3
RE: HP16C display problems
To follow up on Katie's post, here are some tips and pictures showing about Voyager series disassembly.
http://www.decodesystems.com/hp11c-apart.html
Visit this user's website Find all posts by this user
Quote this message in a reply
01-28-2015, 06:48 PM
Post: #4
RE: HP16C display problems
(01-28-2015 03:40 PM)Katie Wasserman Wrote:  I'm not sure if the display connection used on the 16C changed over the years of production. Early ones used zebra pressure connection, these days the 12C uses a soldered connection. You can open up your calculator to have a look. (There is a screw under each rubber foot.)

There definitely ARE different LCD connection types, at least early and late style. Find a cheap donor HP-12C with the same type of battery contacts as your 16C and you should have a matching part (some have 1 spring, some have contacts on both sides, etc.)

--Bob Prosperi
Find all posts by this user
Quote this message in a reply
01-29-2015, 07:01 AM
Post: #5
RE: HP16C display problems
Just one segment being dead indicates that the problem is with the LCD display itself nothing else. You can confirm that it's just one segment by running the standard keyboard/display test <ON> + <divide>. Keep in mind that not all LCD display segments are used in the 16C, but running the keyboard/display test does use all segments.
[/quote]
Thanks for that hint,

I just ran [ON]+[X] which confirmed a single broken segment.

I also ran [ON]+[divide] which confirmed all the keys are in working order.
Find all posts by this user
Quote this message in a reply
09-27-2015, 05:02 PM (This post was last modified: 09-27-2015 05:03 PM by Fabio Muller.)
Post: #6
RE: HP16C display problems
Hello guys, last year a finally bought a HP16C at ebay but there was a little problem with the display that leaked in the middle upper section. It's a small leakage, the display is working and it's readable but I would like to repair. So , I bought I an old used 12C (10,00 bucks, working)) same type of battery connection and so on..., did the surgery, became expert on changing the voyager display, but did not work. It's the rubber one (not soldered) and it's definitely not the same type. The 16C seems a little bit more "greenish" and the 12C pulls more for a yellow (or brown) and I have two 12C and both has the same display. If you look at ebay , the most similar example is the 11C. I think 11C and 16C may share the same display. If I replace the ones I have , it powers on 16C but with some segments off or not well defined. I'm taking all care in put them at the exact position, so that I could get to remove and swap them fine and put back to their original places and they continue to work as before. At first time is a little trick but after some practice you managed it fine. So , my doubt is if somebody already had the same problem or if somebody knows if the displays are different among the voyager series.

Rgds..
Find all posts by this user
Quote this message in a reply
09-27-2015, 05:31 PM
Post: #7
RE: HP16C display problems
(09-27-2015 05:02 PM)Fabio Muller Wrote:  Hello guys, last year a finally bought a HP16C at ebay but there was a little problem with the display that leaked in the middle upper section. It's a small leakage, the display is working and it's readable but I would like to repair. So , I bought I an old used 12C (10,00 bucks, working)) same type of battery connection and so on..., did the surgery, became expert on changing the voyager display, but did not work. It's the rubber one (not soldered) and it's definitely not the same type. The 16C seems a little bit more "greenish" and the 12C pulls more for a yellow (or brown) and I have two 12C and both has the same display. If you look at ebay , the most similar example is the 11C. I think 11C and 16C may share the same display. If I replace the ones I have , it powers on 16C but with some segments off or not well defined. I'm taking all care in put them at the exact position, so that I could get to remove and swap them fine and put back to their original places and they continue to work as before. At first time is a little trick but after some practice you managed it fine. So , my doubt is if somebody already had the same problem or if somebody knows if the displays are different among the voyager series.

Rgds..
See reply from rprosperi above he did find a suitable donor and I did the surgery for him, the donor 12C serial started with 2224A to give you an idea of the time frame it was built.
Find all posts by this user
Quote this message in a reply
09-27-2015, 11:00 PM
Post: #8
RE: HP16C display problems
Thank you for you answer Paul, good to know that someone did it. The one I bought for exchange has s/n starting with 3246B. the other one 3323S. It seems that I should look for 2NNNA series. My 16C has 2522A. I will try to find that and advise later.

(09-27-2015 05:31 PM)Paul Berger (Canada) Wrote:  
(09-27-2015 05:02 PM)Fabio Muller Wrote:  Hello guys, last year a finally bought a HP16C at ebay but there was a little problem with the display that leaked in the middle upper section. It's a small leakage, the display is working and it's readable but I would like to repair. So , I bought I an old used 12C (10,00 bucks, working)) same type of battery connection and so on..., did the surgery, became expert on changing the voyager display, but did not work. It's the rubber one (not soldered) and it's definitely not the same type. The 16C seems a little bit more "greenish" and the 12C pulls more for a yellow (or brown) and I have two 12C and both has the same display. If you look at ebay , the most similar example is the 11C. I think 11C and 16C may share the same display. If I replace the ones I have , it powers on 16C but with some segments off or not well defined. I'm taking all care in put them at the exact position, so that I could get to remove and swap them fine and put back to their original places and they continue to work as before. At first time is a little trick but after some practice you managed it fine. So , my doubt is if somebody already had the same problem or if somebody knows if the displays are different among the voyager series.

Rgds..
See reply from rprosperi above he did find a suitable donor and I did the surgery for him, the donor 12C serial started with 2224A to give you an idea of the time frame it was built.
Find all posts by this user
Quote this message in a reply
Post Reply 




User(s) browsing this thread: