HP Forum Archive 21

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Expected lifetime and failure modes of vintage 15C? Message #1 Posted by Eric Zoob on 21 Mar 2012, 10:21 a.m. Based on the construction materials what is the expected lifetime of the original line of Voyager models? Is there a list of the failure modes for the vintage 15C calculators?

Re: Expected lifetime and failure modes of vintage 15C? Message #2 Posted by Luiz C. Vieira (Brazil) on 21 Mar 2012, 11:09 a.m., in response to message #1 by Eric Zoob HI. I have 2 units, both going to 25 YO. No fails of any kind so far. Some battery changes (I used them a lot, not too much these days, but still using somehow), some cleaning, a lot of care when using (no exposure to harmful environment), and I hope they will go more 25, and even more. Add to these: 2 HP16C, some HP12C (some 15 units, from different 'crops', mostly for training students) and one HP11C. All of the ones in the same 'age range' (~25 YO) are working in a no-fail basis. The new HP12C, though... well, let's say I wish them their best, though they are not the best representatives. I also have an HP15C LE, but I do not use it. It is kind of a memorial to me, you know? There is also an HP10C, unfortunately no longer working (sob...) Well, for me these babies are reliable as hell! (forgive my foreign accent...) Cheers. Luzi (Brazil)

Re: Expected lifetime and failure modes of vintage 15C? Message #3 Posted by uhmgawa on 21 Mar 2012, 11:34 a.m., in response to message #1 by Eric Zoob Quote: Based on the construction materials what is the expected lifetime of the original line of Voyager models? Barring some type of negligent trauma, likely longer than that of the original owner's usage. Quote: Is there a list of the failure modes for the vintage 15C calculators? I've disassembled quite a few casualties and don't believe I've ever encountered a silicon failure. By far the most common functional failure is the elastomer membrane overlaying the snap domes becoming punctured by the keycap actuator probes. This is usually misdiagnosed as a bad tactile dome, yet I don't believe I've ever encountered a worn dome in advance of the membrane becoming punctured through. I have one 11c with a deteriorated hermetic seal in the lcd glass, and I've come across other units rarely exhibiting this defect. Somewhat surprising, I've personally never found a stock unit with bad zebras. The original design where the cpu and r2d2 located on a satellite pcb was interconnected to the keypad pcb by yet another zebra theoretically should be more problematic but I haven't found a failure here in my half dozen or so 30 year old units. Cosmetically the feet tend to decompose after a decade or so and I've seen isolated cases where the bottom legend plate begins to delaminate, however the latter was likely due to rough handling. [edited for clarity] Edited: 22 Mar 2012, 11:28 a.m.

Re: Expected lifetime and failure modes of vintage 15C? Message #4 Posted by From Hong Kong on 21 Mar 2012, 11:59 a.m., in response to message #1 by Eric Zoob Quote: Based on the construction materials what is the expected lifetime of the original line of Voyager models? Is there a list of the failure modes for the vintage 15C calculators? My HP-15C was made in USA. It will be 27 years old after August. No failure of any kind so far.

Re: Expected lifetime and failure modes of vintage 15C? Message #5 Posted by Eric Smith on 21 Mar 2012, 12:48 p.m., in response to message #1 by Eric Zoob Despite what others have said about the longevity of their calculators, the design life of electronic products is generally not more than ten years, and often only five. Statistical measures such as MTBF are only applicable within the design life; beyond that you are on the rising edge of the bathtub curve, where failure rates increase. Obviously some electronic products are better made than others, but nevertheless, if you have a 20+ year old electronic device that still works, consider yourself lucky.

Re: Expected lifetime and failure modes of vintage 15C? Message #6 Posted by Mike Morrow on 21 Mar 2012, 2:22 p.m., in response to message #5 by Eric Smith Quote: ...if you have a 20+ year old electronic device that still works, consider yourself lucky. The population of such products does not seem significantly skewed to HP products either. All my 1978-era Casio units (LCD) still work and have good displays. I'm the original owner of a March 1975 SR-51A and a March 1974 SR-50 that still work well. However, the TI-59 stuff...that was very hard to keep working. I went through five between mid-1977 and mid-1979. I'm the original owner of a July 1977 HP-67 whose card reader hasn't worked in decades. OTOH I've got a fully functional 1976 HP-21 and 1976 HP-25, and even my HP-35 Red Dot works as well as it did forty years ago. All my HP LCD calcs are still 100 percent...I'm thankful in particular that my several twenty-year old HP-42S units work and look like new. Thirty years ago I had expected almost all LCD calcs to end their life with loss of the LCD display before ten years passed, but I've been very pleasantly wrong with that prediction. You asked about Voyagers. The HP-15C I bought 27 years ago and my 26-year old HP-12C are still 100 percent too, except for the chrome paint wearing off the HP badge on the 15C. These devices have far far outlived any originally anticipated service life, just as most personal computers would if technology advances didn't compel their junking. Calculators have been given a big break for retention in spite of obsolescence, doubtless due to their small size and a certain cuteness factor. (Why else would I still have my 1972 Sharp EL-801 ELSIMINI four-banger?)

Re: Expected lifetime and failure modes of vintage 15C? Message #7 Posted by uhmgawa on 21 Mar 2012, 6:31 p.m., in response to message #6 by Mike Morrow Quote: Quote: ...if you have a 20+ year old electronic device that still works, consider yourself lucky. These devices have far far outlived any originally anticipated service life, just as most personal computers would if technology advances didn't compel their junking. Calculators have been given a big break for retention in spite of obsolescence.. The bathtub model may still apply here. But empirically the walls may be pushed apart beyond recognition due to the service factor seen by the majority of devices, combined with a lack of significant electrical, mechanical, and thermal stress inflicted upon typical consumer electronics. I'm not so much amazed any more with the longevity of the above but rather with the lack thereof in other sibling efforts. At least it appears TI was far ahead of the crowd with the concept of disposable electronic recycling.

Re: Expected lifetime and failure modes of vintage 15C? Message #8 Posted by bill platt on 21 Mar 2012, 5:27 p.m., in response to message #5 by Eric Smith New stuff is different. Solder is not lead. How about capacitor materials?. Resistors? Old Vacuum tube radios (dead bug construction) Would see tube replacement (a normal thing) blown caps, bad potentiometers, fried transformer or inductor windings, failed insulation on wires....And yet you could still find 40 year old or older sets working fine. I Have a GONSET Coummunicator AM VHF Transceiver (crystal) which worked just fine 10 years ago when I got it. I haven't cranked it up lately--probably won't be so lucky now...but it was over 40 years old... Edited: 21 Mar 2012, 5:28 p.m.

Re: Expected lifetime and failure modes of vintage 15C? Message #9 Posted by Valentin Albillo on 22 Mar 2012, 7:16 a.m., in response to message #5 by Eric Smith Hi, Eric: Quote: Obviously some electronic products are better made than others, but nevertheless, if you have a 20+ year old electronic device that still works, consider yourself lucky. Matter of fact, I have *many* 20+ yo and 30+ yo electronic devices that still work as new and look as new to boot, including calculators, cassette players, CD players, cameras, whatever. The most remarkable, IMHO, is this Sony D-50 portable CD-player about 30 years old and utterly like new despite heavy use: I use it rarely now as it doesn't play MP3 (of course !) but last month I listened to 3 brand-new audio CDs I bought and it sounded as wonderfully as ever. By the way, I don't consider myself "lucky", actually I think luck plays a small part, the really big part being played by manufacturing quality and careful use. Quality items were built to last back then, unlike today's throwaway items pre-programmed for automatic obsolescence so that after a year or two they'll either stop functioning altogether o simply be considered out of fashion despite still being perfectly functional (cough, *cell phones*, cough). Best regards from V.

Re: Expected lifetime and failure modes of vintage 15C? Message #10 Posted by bill platt on 22 Mar 2012, 11:10 a.m., in response to message #9 by Valentin Albillo I have this rough and ready theory of the "ten year peak" in quality (the actual number of years is inexact.) Essentially it seems to me that new technologies first need to be shown to work and be reliable for market acceptance. This leads to a level of care and overbuilding, which after a few initial years of possible mistakes, leads to robust products. Thereafter, production "efficiencies" become paramount and the build quality declines--often precipitously. Comparing my old 1985 VHS machine (100" metal chassis, most moving parts brass) to the last one I bought (100% plastic chassis, 90% plastic moving parts) gives a good example quite similar to your above example. HP essentially peaked in the Voyagers, which are roughly 10 years after the 35. The Pioneers and Champagnes are nearly as robust, which I think shows the strength of the old HP's feelings about quality.

Re: Expected lifetime and failure modes of vintage 15C? Message #11 Posted by Valentin Albillo on 22 Mar 2012, 12:33 p.m., in response to message #10 by bill platt Quote: HP essentially peaked in the Voyagers, which are roughly 10 years after the 35. The Pioneers and Champagnes are nearly as robust, which I think shows the strength of the old HP's feelings about quality. Agreed. The HP-71B is also another pinnacle of build quality, really state-of-the-art, I can't think of any other model as well built and as durable as it, not certainly the feeble, plasticky HP-41C variants. BTW: Not only is it beautiful and sturdy but also extremely capable. I was made aware of Project Euler a few days ago thanks to the recent "Sunday challenge" by Allen, and decided to try and solve as many problems as my scarce free time allows by using exclusively the HP-71B in its free, excellent emulated incarnation by J-F Garnier, Emu71. So far I've tackled about 30 problems there with complete success, most of them solved using very, very few lines of HP-71B code (less than 10). Time permitting, I intend to solve them all in time and eventually create a PDF collection of my commented HP-71B solutions. Best regards from V.

Re: Expected lifetime and failure modes of vintage 15C? Message #12 Posted by bill platt on 22 Mar 2012, 2:17 p.m., in response to message #11 by Valentin Albillo I always think of the 71B as "giant" cousin of the voyagers, and I guess it really is, physically at least. I don't own one, but the former VP of my former company had one and was still using it in 2006 even though he was a total new gadget freak. The 71B stood the test of time for him.

Re: Expected lifetime and failure modes of vintage 15C? Message #13 Posted by Garth Wilson on 22 Mar 2012, 6:17 p.m., in response to message #11 by Valentin Albillo Of the many, many electronic devices I bought in the 70's and 80's, a very small percentage of them have had any failures outside of things like rotting rubber belts, gummy wheels, and rechargeable batteries that no longer held a charge. I still use much of this equipment, especially the workbench test equipment. Even of my four TI-58's & 59's, only one ever had an electronic problem, and that was that it quit reading the module. The other calcs of that era all keep working too, although I only get them out occasionally just to see them work. Of my HP-41 and 75 and two 71's and the many peripherals and accessories, the only things to fail have been the Thinkjet printer and, just this year, the 96KB CMT cardreader-port memory module for the 71, which looks exactly like Valentin's above. (Anyone know how to fix them? Please?) I've had a few PCs & disc drives go down, but they were made more recently, starting about 1990, and they're made absolutely as cheaply as possible and the manufacturers expect that you'll be replacing every couple of years.

Re: Expected lifetime and failure modes of vintage 15C? Message #14 Posted by Fabricio on 22 Mar 2012, 3:58 p.m., in response to message #10 by bill platt Quote: HP essentially peaked in the Voyagers, which are roughly 10 years after the 35. The Pioneers and Champagnes are nearly as robust, which I think shows the strength of the old HP's feelings about quality. And quality decay after that came not only to HP calculators, but for every single thing we buy now. I think sometimes we hit strong HP because of the cheapness of their newer calculators, but compared to today production standards probably they are ok (I am not talking about design nor firmware bugs)and we are a bit unfair in judging them. We knew the old products, not only HPs, and that´s the reason why we stick to and demand that quality, but again those days are gone for everything. My usd$2E-2.

Re: Expected lifetime and failure modes of vintage 15C? Message #15 Posted by uhmgawa on 23 Mar 2012, 2:24 p.m., in response to message #10 by bill platt Quote: I have this rough and ready theory of the "ten year peak" in quality (the actual number of years is inexact.) I'd go along with that theory as I've observed about the same syndrome. It is almost comical to have a peek inside some of these products just prior to them having fallen over the knee in the obsolescence curve. Molded nylon/delrin mechanisms drenched in lithium grease and press-fit assembled with a short prayer they'll never be seen again. But more to the point of this thread.. although perhaps a substantially protracted degradation, the calculators we huddle around here are still regrettably on a slow ride to the junk pile. However except for those with specialized mechanical components they are arguably reproducible with comparatively little up-front tooling cost relative to other consumer electronic devices. At least that's my excuse for the continued preoccupation leveraging legacy firmware emulation as a more abstract preservation approach.

Re: Expected lifetime and failure modes of vintage 15C? Message #16 Posted by Andrés C. Rodríguez (Argentina) on 22 Mar 2012, 12:24 p.m., in response to message #9 by Valentin Albillo Hi Valentín, I also had a Sony D-50, bought in NYC in 1985. While I liked it a lot, and treated it with lots of care, it developed kind of an age-related illness: difficulty to keep the optics focused on the track. It seems that there is an elastic component in the focus mechanism, and that such component loses its elasticity over time. Of course, analogies with human eyes and their (or, better, our!) loss of ability to focus after age 40-50 are possible. In my experience, CD players more than 8 to 10 years old suffer from this kind of problem, which promotes their replacement no matter how much we cared about them, nor how fond of them we are. Just my AR$ 0.10

Re: Expected lifetime and failure modes of vintage 15C? Message #17 Posted by Valentin Albillo on 22 Mar 2012, 4:48 p.m., in response to message #16 by Andrés C. Rodríguez (Argentina) Hi, Andrés: Quote: It seems that there is an elastic component in the focus mechanism, and that such component loses its elasticity over time. Of course, analogies with human eyes and their (or, better, our!) loss of ability to focus after age 40-50 are possible. Mine still hasn't developed that fault or any other for that matter but a wonderful Sanyo "Walkman" cassette player I had owned for decades recently suffered from exactly the same malady you describe, some plastic and/or elastic components wholly deteriorated in time (25 years no less !) and renderer it unusable and probably unrepairable as well. It had such unique features as a built-in mic so that you could listen to someone talking to you without removing your headphones or even lowering the volume, variable play speed, twin headphone outlets, the works. May it rest in peace ! ... :) Best regards from V.

Re: Expected lifetime and failure modes of vintage 15C? Message #18 Posted by uhmgawa on 23 Mar 2012, 9:29 a.m., in response to message #16 by Andrés C. Rodríguez (Argentina) Quote: It seems that there is an elastic component in the focus mechanism, and that such component loses its elasticity over time. IIRC from my repairs in the past, the magnetic voice coil is biased via a spring suspension which attempts to locate the lens assembly at mid travel irrespective of unit orientation. Presumably this was in part an effort to control power consumption such that on average the focus servo current would be minimized. I think over time the purposefully engineered lightweight suspension ages with its displacement drifting off center for which the servo drive may not be able to accommodate under all conditions. I recall some units provided service adjustments to compensate for this scenario but personally I'd only realized lukewarm results at best. It is a marvel of electro/mechanical control technology particularly for its time and even more so in the volumes it was reliably (+/-) manufactured. No one however could have been more happy than I to see solid state media displace that technology in portable applications. The often associated audio compression paring however is it's own never ending debate.

Re: Expected lifetime and failure modes of vintage 15C? Message #19 Posted by Andrés C. Rodríguez (Argentina) on 23 Mar 2012, 9:41 a.m., in response to message #18 by uhmgawa I do agree with your detailed description and experience. Lukewarm and short-lived results here too (trying to make the servo compensate for the aged focus system).

Re: Expected lifetime and failure modes of vintage 15C? Message #20 Posted by Mike Morrow on 22 Mar 2012, 1:24 p.m., in response to message #9 by Valentin Albillo Quote: The most remarkable, IMHO, is this Sony D-50 portable CD-player about 30 years old and utterly like new despite heavy use... That's one data point for the D-50. The D-50 was my first audio CD player, purchased in 1985. I never used it portable...it was my nightstand CD player that was used about two hours each week. It died irreparably when the laser head started searching without finding the track...even after repeated attempts to wipe the laser head lens. That was 1988. Three years service from a fairly expensive item. Just another data point. Right now the longest-lived, still working, electronic item for which I was the original purchaser is my 1974 Texas Instruments SR-50.

Re: Expected lifetime and failure modes of vintage 15C? Message #21 Posted by Don Shepherd on 22 Mar 2012, 3:17 p.m., in response to message #20 by Mike Morrow Here's one more data point on that beautiful Sony D-50. Like Mike, it was my first CD player. I put cassette tapes behind me and never looked back. Also like Mike, I never used it as a portable, I hooked it into a Radio Shack audio amplifier with a decent set of speakers and the music was great. I've had many CD players since then--portable and console--but my D-50 is still going strong, currently hooked to a much bigger amplifier and speakers and still renders the Hotel California such that it would bring tears to your eyes! I have not joined the MP3 i-device audio generation and have no intention of doing so. I expect CDs to last me the rest of my life.

Re: Expected lifetime and failure modes of vintage 15C? Message #22 Posted by M. Joury on 22 Mar 2012, 3:31 p.m., in response to message #21 by Don Shepherd It was also my first CD player. Back then it was a heck of a lot of money for me but I never regretted it. Mine was still going strong last time I tried a couple of years back. It is stored somewhere now and I will undoubtedly come across it when I move again middle of this year. I'll have to take it out and make sure it is still working--I'm sure it will be :). Cheers, -Marwan

Re: Expected lifetime and failure modes of vintage 15C? Message #23 Posted by Paulo MO on 21 Mar 2012, 6:16 p.m., in response to message #1 by Eric Zoob Even though this is not (by far) a failure, there seems to exist a pattern that bothers me a tiny little bit (at least I detected it in many of the two dozens or so 20+ old voyager machines I played with). I don't know if I can accurately describe it in words. It relates to the plastic sheet wrapping the domes assembly. With age, the plastic sheet seems to loose adherence to the domes and, when we press and then release a key, we can hear the plastic adhering and separating again from the domes, on release. It makes a plastic wrap noise which neither God nor HP intended us to hear. One should hear and feel a "click", not a "click" and a "shhk". I once destroyed a 12C just to get access to the plastic sheet, and press it again against the domes, in order for it to adhere again. That part of the "repair" worked fine, by I got into trouble afterwards, when trying to repair the heat stakes; bottom line:no more "shhk", no plastic wrap noises, but no 12C either. With hindsight, I now think It would have been beter to leave the "shhk" alone :-) Best Paulo Edited: 21 Mar 2012, 6:16 p.m.

Re: Expected lifetime and failure modes of vintage 15C? Message #24 Posted by Matt Agajanian on 21 Mar 2012, 6:35 p.m., in response to message #23 by Paulo MO Thus giving more credence and stronger validation to the old adage, "If it ain't broke, don't fix it." But, in all sincerity, thanks for sacrificing your 12C to teach us all this crucial lesson. I hope you find a superb, NIB, Mint or other high quality replacement Vintage 12C soon.

Re: Expected lifetime and failure modes of vintage 15C? Message #25 Posted by uhmgawa on 21 Mar 2012, 9:07 p.m., in response to message #23 by Paulo MO Quote: I once destroyed a 12C just to get access to the plastic sheet, and press it again against the domes, in order for it to adhere again. That part of the "repair" worked fine.. I believe the film adhesive starts to "ball up" and migrate with repeated mate/peel cycles, to the point the original surface area is reduced which accelerates the deterioration. Replacement is probably a better approach. Unsure what type of adhesive was used originally but IIRC it was necessary to use carb cleaner to free the domes and PCB of the goo. Quote: I got into trouble afterwards, when trying to repair the heat stakes; bottom line:no more "shhk", no plastic wrap noises, but no 12C either. I've had fairly good luck using acetone to solvent weld new ABS heads on the heat stakes. I've used both an ad-hoc jig and a small drill press to apply pressure to the replacement head until the acetone flashes off. Doing so compresses the elastic membrane giving a snug fit. It is a bit tedious restoring one stake at a time but it does go relatively quick.

Re: Expected lifetime and failure modes of vintage 15C? Message #26 Posted by Ron Ross on 21 Mar 2012, 9:18 p.m., in response to message #1 by Eric Zoob Originally, I suspect that Hp themselves would have stated 5 years, as the voyage series were considered calculation insturments or tools. However, they were the last calculators from Hp that were designed to be serviced. I used my Hp 15c extensively for about eight years before I bought an Hp 42s. And I still have that Hp 15c and it still works like new. I believe the voyager series calculator is the most rugged line of production calculators ever made by anyone. With heavy use (not abuse) I suspect 20 maybe even 30 years would be a very good estimate for the MTBF value as the older Hp 12c is identical in construction and you don't hear about to many failures with that machine either.

Re: Expected lifetime and failure modes of vintage 15C? Message #27 Posted by Fabricio on 21 Mar 2012, 10:26 p.m., in response to message #26 by Ron Ross Quote: With heavy use (not abuse)... My 11C has the following symptoms: the keyboard rattles a lot when shaking the calculator, although still can press on any key, and the main issue is that the point and coma are not longer distinguishable, and even at any given time you see several decimal points in the display so can´t clearly identify what´s the number there. But mine is a case of abuse. I have described in other threads that I used it in my high school and college years, and am pretty sure I dropped it from a second floor, probably not once but twice at least. Also, I didn´t use any school bag, so most times I had a bunch of notebooks and the calculator pressed against one hand and my waist; actually I think this is the reason why the calculator has problems with the display. Its service life went from 1988 to 1999-2000, but with periods without use (probably on the order of a 7-years effective life)

Re: Expected lifetime and failure modes of vintage 15C? Message #28 Posted by uhmgawa on 25 Mar 2012, 11:52 a.m., in response to message #26 by Ron Ross Quote: However, they were the last calculators from Hp that were designed to be serviced. Well, maybe sort of. Unfortunately the most frequent repairs are due to keyboard malfunctions and 41 service unfriendly write-once heat stakes are between you and the problem. Same for getting at the lcd to reseat the zebras or even clean off dust which has crept between it and the window. I'd agree getting in the enclosure is far more straightforward vs. say the inexplicably service hostile 42s, but that's about all unfortunately. The sam7 voyagers are better in this respect as the lcd can be repositioned for cleaning or window replacement. And while it still suffers from heat stakes, far fewer exist and once cut each can be restored via an M1.2 or M1.4 screw due to the (coincidental?) hollow molded in the center of each stud. Quote: I believe the voyager series calculator is the most rugged line of production calculators ever made by anyone. Probably true. I suppose the above service shortcomings are more/less in the noise when a product has been designed not to require service in its expected lifetime.

Re: Expected lifetime and failure modes of vintage 15C? Message #29 Posted by Eddie W. Shore on 21 Mar 2012, 11:38 p.m., in response to message #1 by Eric Zoob My vintage one is a 1986 15C and still going strong other than the minor wear and the emblem falling off. The contents inside is still going good.

Re: Expected lifetime and failure modes of vintage 15C? Message #30 Posted by Dwight Sturrock on 21 Mar 2012, 11:58 p.m., in response to message #29 by Eddie W. Shore Mine is from 1983 (29 years) and still works fine. The emblem fell off years ago.

Re: Expected lifetime and failure modes of vintage 15C? Message #31 Posted by Juan J on 22 Mar 2012, 12:02 p.m., in response to message #30 by Dwight Sturrock Hello, Both my 10C and 12C will turn 30 in a few weeks. The latter had its first battery change in 2003 and it is still going strong. I use both every other day for quick calculations at home. My 15C is 27 years old and still sees daily use with the ex missus. Thankfully, we parted amicably and I kept the collection intact. But that is another story. Juan Edited: 22 Mar 2012, 12:03 p.m.

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