Author Topic: *** SOLD*** HP3456a 6 digit DMM  (Read 16421 times)

0 Members and 1 Guest are viewing this topic.

Offline tecmanTopic starter

  • Frequent Contributor
  • **
  • Posts: 444
  • Country: us
*** SOLD*** HP3456a 6 digit DMM
« on: May 09, 2010, 12:35:31 am »
I have an HP 3456a 6 digit meter for sale.  In great shape.  I have had it for a number of years and have not used it for a few of years, so perhaps someone else can use it in their home lab.  Full features + HPIB

I am looking for $ 100.00 firm + UPS costs to ship.  USA only

Let me know if you are interested.

Paul


Sorry it's sold

Paul
« Last Edit: May 16, 2010, 10:03:47 pm by tecman »
 

Offline tecmanTopic starter

  • Frequent Contributor
  • **
  • Posts: 444
  • Country: us
Re: HP3456a 6 digit DMM
« Reply #1 on: May 10, 2010, 07:40:01 pm »
I would prefer to sell and ship in the US, as international sales is always a bit of a hassle.

Paul
 

Offline Simon

  • Global Moderator
  • *****
  • Posts: 17816
  • Country: gb
  • Did that just blow up? No? might work after all !!
    • Simon's Electronics
Re: HP3456a 6 digit DMM
« Reply #2 on: May 10, 2010, 08:24:14 pm »
to whoever buys out of the USA beware of import duty as this will be your problem (often cause of misunderstanding on eBay)
 

Offline Rowland

  • Newbie
  • Posts: 6
Re: HP3456a 6 digit DMM
« Reply #3 on: May 14, 2010, 02:12:56 pm »
Import Duty is the least of your problems, Its the V.A.T. that will be charged and this will also be on the shipping
 

Offline Kiriakos-GR

  • Super Contributor
  • ***
  • !
  • Posts: 3525
  • Country: gr
  • User is banned.
    • Honda AX-1 rebuild
Re: HP3456a 6 digit DMM
« Reply #4 on: May 14, 2010, 02:23:37 pm »
Anything under 100 EUR cost and shipping, are tax free at list in Greece.
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 37740
  • Country: au
    • EEVblog
Re: HP3456a 6 digit DMM
« Reply #5 on: May 14, 2010, 10:56:25 pm »
In Australia we don't pay any import tax or duty for anything (or total orders) under $1000. But the shipped cost to Oz for big heavy gear like this is ridiculous.

Dave.
 

Offline rf-loop

  • Super Contributor
  • ***
  • Posts: 4105
  • Country: fi
  • Born in Finland with DLL21 in hand
Re: HP3456a 6 digit DMM
« Reply #6 on: May 15, 2010, 06:58:55 am »
HP3456A is very good DVM. (if it is in good condition still and nobody have "repair" and "adjust" it.)
There is not so much different functions but it is extremely accurate and what is better, it also keep its accuracy.
It is not made so that last digit is only some kind of resolution but no accuracy. Many meters today have many digits, yes some kind of resolution is high but real accuracy... there are lot of nice look toys. Display digits are cheap. Real accuracy is not cheap. This HP is not toy. Also construction is very special. Including some part of special soldering in "front end".
Also it is 7 1/2 digit.  (in slow mode) Max 6 1/2 in normal mode.  But IMHO most of peoples do not know nearly anything about accurate measurements (including me), how to do and so on... so most of peoples (including also many professionals) can not use this accuracy in real. This DVM is very accurate and stability is extremely good. But yes you can check if 3-4 digit plastic box fluke is enough accurate.

Also becouse its special mechanical construction it need ship very careful. (measuring part is isolated from other all parts. Even communication between logig/processor is isolated. This isolation is easy fragile in "wrong" service or in shipping without enough damping material.

If this kind of meter is in original condition I want buy it if I can get it with reasonable price.  But shipping cost is of course too much.
In EU (some developed parts of) we have rule that outside from EU we pay TAX (VAT) and customs if value with shipping is more than 50EUR. (If Greege do it different maybe Greege need change it later after they understan all about EU where they now are. There are not free dinners. Also here we have change many international shopping taxations after EU have make some command. (specially with second hand cars from other country)

I have never understand one thing in USA (specially ebay). How it is so difficult to send items to foreign countries. ( if buyer pay all shipping.)

 Also sending money to usa is very difficult. Can not use any automatic transfers becouse they banks are not connected to computers ( ;) ). Only posibility is credid card directly (do not) and example Paypal (expensive). I can send money very easy from my bank to China, all eu countries and many other but always I send to USA it is extremely difficult. (and very slow and very expensive)

Shipping to foreign country. Here we have postal office on near every streets corner and we can send packages to foreign countries where ever we want just as easy as in domestic. If I want send to USA I write address on package and thats all. What is there so difficult? Maybe US need also wake up to this global world. I can very easy buy from China, Japan, EU all countries, South-Africa, Mexico, Australia but buy from USA... they do not want ship or they can not. ;) Also it is very easy to write CN22 form or other papers to shipment. Rules are very simple and easy. Writing these papers is very very easy if can read and write. It takes maybe 3 minutes and pen. Just as easy as write adress.

Back to topic. If I can here get this 2456A with 70 - 80Eur to my hand and it is good condition. I think I have make very good deal! With this price I want buy as many as I can find.  (after guality check and some small adjustment check it is perfect meter what rivals many new meters in stability)
I can not get any new this quality meter with this price. I need put one decade more to price if want new this accuracy and  other quality. (including available documents. You can also really know how to calculate possible errors so you can do some  scientific also)

(I have sell these starting from 250Eur.  And  "brother" of this 3455A also.  Not any kind of "ebay scrap and junk" where seller tell that he do not know anything other but there is some light in the box after power up)

Maybe today many peoples can not know how good these old equipments are. But many peoples want plastic small colorlighted box.

« Last Edit: May 15, 2010, 07:46:30 am by rf-loop »
I drive a LEC (low el. consumption) BEV car. Smoke exhaust pipes - go to museum. In Finland quite all electric power is made using nuclear, wind, solar and water.

Wises must compel the mad barbarians to stop their crimes against humanity. Where have the wises gone?
 
The following users thanked this post: elecdonia

Offline Kiriakos-GR

  • Super Contributor
  • ***
  • !
  • Posts: 3525
  • Country: gr
  • User is banned.
    • Honda AX-1 rebuild
Re: HP3456a 6 digit DMM
« Reply #7 on: May 15, 2010, 09:02:13 am »

In EU (some developed parts of) we have rule that outside from EU we pay TAX (VAT) and customs if value with shipping is more than 50EUR. (If Greege do it different maybe Greege need change it later after they understan all about EU where they now are. There are not free dinners. Also here we have change many international shopping taxations after EU have make some command. (specially with second hand cars from other country)

Save your ranting , because you just reveal how poor information you got about the EU and imports.
Every items category has an specific tax rate ..  an specific code as  item , look for it at the European web site ...

Now lets stop writing irrelevant comments.
Because we probably spam the mailbox of this member,
by getting  email notifications about new replies .    

 

Offline personalinformatics

  • Newbie
  • Posts: 7
Re: HP3456a 6 digit DMM
« Reply #8 on: May 15, 2010, 03:39:49 pm »
Message sent. Can provide a HP3456a a nice home : ).

In current need of making accurate resistance measurements to build a pair of precision stepped attenuators. (8 resistors per 45 steps . . . 360 resistors per channel . . .)

Thanks!
« Last Edit: May 15, 2010, 03:48:22 pm by personalinformatics »
 

Offline saturation

  • Super Contributor
  • ***
  • Posts: 4787
  • Country: us
  • Doveryai, no proveryai
    • NIST
Re: HP3456a 6 digit DMM
« Reply #9 on: May 16, 2010, 01:39:58 pm »
I am in the process of buying it too!  We shall see.  Sorry I should have posted about it earlier, but I forgot to post here rather than PM.

Message sent. Can provide a HP3456a a nice home : ).

In current need of making accurate resistance measurements to build a pair of precision stepped attenuators. (8 resistors per 45 steps . . . 360 resistors per channel . . .)

Thanks!
Best Wishes,

 Saturation
 

alm

  • Guest
Re: HP3456a 6 digit DMM
« Reply #10 on: May 16, 2010, 02:56:14 pm »
Tecman will just do like Solomon, take a saw, split it in two, and send you both half of it for $50 ;).
 

Offline personalinformatics

  • Newbie
  • Posts: 7
Re: HP3456a 6 digit DMM
« Reply #11 on: May 16, 2010, 06:24:39 pm »
From the pics, it looks like it is already up on a tablesaw. lol

I'm good either way. Just need to know, if saturation is not going to buy it.
 

Offline Kiriakos-GR

  • Super Contributor
  • ***
  • !
  • Posts: 3525
  • Country: gr
  • User is banned.
    • Honda AX-1 rebuild
Re: *** SOLD*** HP3456a 6 digit DMM
« Reply #12 on: May 16, 2010, 11:00:43 pm »
Who got it  ?? 
 

Offline personalinformatics

  • Newbie
  • Posts: 7
Re: *** SOLD*** HP3456a 6 digit DMM
« Reply #13 on: May 17, 2010, 12:01:17 am »
I'm not sure, but I can provide a "ship to" address.  ::)

Let me know, in the next day or so, if the deal happens to fall through.
 

Offline tecmanTopic starter

  • Frequent Contributor
  • **
  • Posts: 444
  • Country: us
Re: *** SOLD*** HP3456a 6 digit DMM
« Reply #14 on: May 17, 2010, 12:13:47 am »
Can't kiss and tell.

Let the buyer boast.

Paul
 

Offline saturation

  • Super Contributor
  • ***
  • Posts: 4787
  • Country: us
  • Doveryai, no proveryai
    • NIST
Re: *** SOLD*** HP3456a 6 digit DMM
« Reply #15 on: May 17, 2010, 03:53:15 pm »
I'm the lucky one.  By chance tecman and I live within driving range of each other, which simplified shipping, costs, and logistics.

It was a pleasure to meet him.

If anyone is still interested, there are a number of 3456A in similar price ranges currently on eBay, including the newer 3457A and more.

Best Wishes,

 Saturation
 

Offline Kiriakos-GR

  • Super Contributor
  • ***
  • !
  • Posts: 3525
  • Country: gr
  • User is banned.
    • Honda AX-1 rebuild
Re: *** SOLD*** HP3456a 6 digit DMM
« Reply #16 on: May 17, 2010, 07:40:14 pm »
Congrats ....  If it was not sold in to a forum member , I was ready to start shooting on the seller.  ;D

Its a pleasant surprise, of finding in this place (forum), lots of honesty..

Regards to all .

  
 

Offline personalinformatics

  • Newbie
  • Posts: 7
Re: *** SOLD*** HP3456a 6 digit DMM
« Reply #17 on: May 18, 2010, 04:57:00 am »
Of course, the 3458A's are REALLY sweet but I can only look. I'm considering a Fluke too . . . or Smart Tweezers . . . j/k
« Last Edit: May 18, 2010, 05:56:05 am by personalinformatics »
 

Offline Joy at MCS

  • Regular Contributor
  • *
  • Posts: 88
  • Country: 00
Re: *** SOLD*** HP3456a 6 digit DMM
« Reply #18 on: May 18, 2010, 02:13:43 pm »
Congrats! They are good units and the price paid was  really good deal  :)
 

Offline saturation

  • Super Contributor
  • ***
  • Posts: 4787
  • Country: us
  • Doveryai, no proveryai
    • NIST
Re: *** SOLD*** HP3456a 6 digit DMM
« Reply #19 on: May 18, 2010, 03:07:15 pm »
I've never bought something off someone of the Internet in a direct exchange, so we chatted on phone calls, and I guess we 'interviewed' each other enough to know we weren't off to no good on both our ends.  Then we met in a public place.  I guess this is what secret agents feel like every day.  8)

As I wrote on another post, one still can't be sure buying off an unknown on the Internet whether the device is advertised to work, is what it is described to be, etc., that's why eBay adds some safeguards and emphasizes the need to tell it like it is.  However, you can tell from what people say in an interview just how well things are, and other subtle cues.

Given its a c1982 design, how much longer it will continue to function is unknown.  Like some 'classic' or antique instruments I've already bought for other reasons, its good to first locate manuals especially schematics, find parts suppliers, and read reviews on prior owners on what failed to date.  The 3456A has a large footprint because the components are widely spaced, it has many discrete elements and few ICs, The power consumption and ambient quiescent heat generation is below the ratings of many of its parts, I've monitored actuals at no more than 30W AC, and zero when off, so unless it was maltreated and sat in hot climates, it got a lot of life presumed left in it.

http://en.wikipedia.org/wiki/Failure_modes_of_electronics

[ not my lab, but author claims it was built on eBay auctions ]

 

  

Congrats ....  If it was not sold in to a forum member , I was ready to start shooting on the seller.  ;D

Its a pleasant surprise, of finding in this place (forum), lots of honesty..

Regards to all .

  
« Last Edit: May 19, 2010, 11:03:01 am by saturation »
Best Wishes,

 Saturation
 

alm

  • Guest
Re: *** SOLD*** HP3456a 6 digit DMM
« Reply #20 on: May 18, 2010, 04:27:44 pm »
Given its a c1982 design, how much longer it will continue to function is unknown.
The actual life is always unknown until in dies ;). There's no such thing as a programmed max. life span. It's designed so a certain percentage will still be working after the designed life span. These target percentage and life span back then by HP for a top-of-the-line piece of equipment are probably much higher than for current consumer equipment from any consumer equipment manufacturer (which ironically includes HP). The probability of failure might raise slightly after this time, but many electronics components are likely to live on for a very long time if they don't die as an infant. They have been burned in for almost thirty years (if it was actually produced in 1982) ;). Look at the Mars Rovers, designed to be likely to work for at least 90 days (with some safety margins I'm sure, since RMA is even more expensive than on earth), actually survived for years. It didn't blew up on day 91 as you might expect from the design lifespan. Plenty of equipment built in the sixties that still works (probably not with the original tubes, but these were designed to be replaced periodically). It depends more on the storage and amount of use it saw than on actual age. Electrolytics can be a problem, but then again, some electrolytics from 50+ years old that still work, and plenty five years old electrolytics that are already dead.

There's one known issue with the 3456A, and that is that the ROM's are known to fail. The contents and instructions for replacement are available online, so not a big deal. Not a lot of reports of 3456A's (or other instruments from similar vintage) dieing, though. This instrument was used for a long time in a lot of places, especially since the 3457A didn't offer much advantages (lousy display, but faster, higher resolution via GPIB only, stability slightly worse, more features like current measurement).
 

Offline Kiriakos-GR

  • Super Contributor
  • ***
  • !
  • Posts: 3525
  • Country: gr
  • User is banned.
    • Honda AX-1 rebuild
Re: *** SOLD*** HP3456a 6 digit DMM
« Reply #21 on: May 18, 2010, 05:35:07 pm »
so unless it was maltreated and sat in hot climates, it got a lot of life presumed left in it.

If you have such a fear , you should buy from Germany,  great cool climate and lots of sausages  ;D

I have got many items from ebay , only very few "sellers" tried to play games,
and they got Hell in return  ;D

Probably by buying  photographic equipment - or all short of tools - or motorcycle parts,
or expensive electronic devices ,  you are partially safer , because the owners of them are educated and they do no play games ..

I am fearless on eBay , some times I deliberately  buy dead devices and repair them,
it saves more cash than any other way ..  ;)      
 

alm

  • Guest
Re: *** SOLD*** HP3456a 6 digit DMM
« Reply #22 on: May 18, 2010, 06:01:36 pm »
I am fearless on eBay , some times I deliberately  buy dead devices and repair them,
it saves more cash than any other way ..  ;)      
You mean it saves more cash than buying working equipment and smashing it? ;)
 

Offline Kiriakos-GR

  • Super Contributor
  • ***
  • !
  • Posts: 3525
  • Country: gr
  • User is banned.
    • Honda AX-1 rebuild
Re: *** SOLD*** HP3456a 6 digit DMM
« Reply #23 on: May 18, 2010, 06:30:26 pm »
You mean it saves more cash than buying working equipment and smashing it? ;)

You got me   ;D ... I am unable to smash things ..
Deep in me , I feel like a Doctor , I like only to cure the damaged devices, so to become useful again.

I had smash things , but only when my fourth attempt to bring them in life , was a failure.
I such a case I have all ready lost about 10 hours dealing with it, and I feel excused to smash it  ;D ;D
« Last Edit: May 18, 2010, 06:32:16 pm by Kiriakos-GR »
 

Offline saturation

  • Super Contributor
  • ***
  • Posts: 4787
  • Country: us
  • Doveryai, no proveryai
    • NIST
Re: *** SOLD*** HP3456a 6 digit DMM
« Reply #24 on: May 18, 2010, 09:05:24 pm »
I'm glad you are so bold!  ;D

The whole point of buying is getting what you pay for, if you want damaged or old that's fine.   But I worry more if the seller is truly selling what is written, that's why the reputation is important and in many high end electronic test equipment sellers, the reputations aren't large, usually 100-200 range.

In eBay you pay first, receive item later.  So buyer are out money first before goods are received and in some instances it not easy to stop the payment.  In the USA, entire sections of the FTC, FBI, Dept of Justice, and many attorney General's have entire departments dedicated to Internet fraud and some just to eBay, because a lot of people take advantage of the pay first issue.

http://www.ftc.gov/bcp/icpw/comments/ebay.htm

http://www.justice.gov/criminal/fraud/internet/

http://www.fbi.gov/cyber/cysweep/cysweep1.htm


so unless it was maltreated and sat in hot climates, it got a lot of life presumed left in it.

If you have such a fear , you should buy from Germany,  great cool climate and lots of sausages  ;D

I have got many items from ebay , only very few "sellers" tried to play games,
and they got Hell in return  ;D

Probably by buying  photographic equipment - or all short of tools - or motorcycle parts,
or expensive electronic devices ,  you are partially safer , because the owners of them are educated and they do no play games ..

I am fearless on eBay , some times I deliberately  buy dead devices and repair them,
it saves more cash than any other way ..  ;)     

Best Wishes,

 Saturation
 

Offline saturation

  • Super Contributor
  • ***
  • Posts: 4787
  • Country: us
  • Doveryai, no proveryai
    • NIST
Re: *** SOLD*** HP3456a 6 digit DMM
« Reply #25 on: May 18, 2010, 09:26:03 pm »
Yes, what I meant was its had its share of life's experience  :'( who knows what it went through, always good to know its pedigree to 'guestimate' its remaining life.

http://www.vias.org/transistor_basics/transistor_basics_07_05_01.html

Thanks for the tip about the ROMs, I'll keep a look out.

Given its a c1982 design, how much longer it will continue to function is unknown.
The actual life is always unknown until in dies ;). There's no such thing as a programmed max. life span. It's designed so a certain percentage will still be working after the designed life span. These target percentage and life span back then by HP for a top-of-the-line piece of equipment are probably much higher than for current consumer equipment from any consumer equipment manufacturer (which ironically includes HP). The probability of failure might raise slightly after this time, but many electronics components are likely to live on for a very long time if they don't die as an infant. They have been burned in for almost thirty years (if it was actually produced in 1982) ;). Look at the Mars Rovers, designed to be likely to work for at least 90 days (with some safety margins I'm sure, since RMA is even more expensive than on earth), actually survived for years. It didn't blew up on day 91 as you might expect from the design lifespan. Plenty of equipment built in the sixties that still works (probably not with the original tubes, but these were designed to be replaced periodically). It depends more on the storage and amount of use it saw than on actual age. Electrolytics can be a problem, but then again, some electrolytics from 50+ years old that still work, and plenty five years old electrolytics that are already dead.

There's one known issue with the 3456A, and that is that the ROM's are known to fail. The contents and instructions for replacement are available online, so not a big deal. Not a lot of reports of 3456A's (or other instruments from similar vintage) dieing, though. This instrument was used for a long time in a lot of places, especially since the 3457A didn't offer much advantages (lousy display, but faster, higher resolution via GPIB only, stability slightly worse, more features like current measurement).
Best Wishes,

 Saturation
 

Offline tecmanTopic starter

  • Frequent Contributor
  • **
  • Posts: 444
  • Country: us
Re: *** SOLD*** HP3456a 6 digit DMM
« Reply #26 on: May 18, 2010, 10:27:53 pm »
Nice to see that I was somehow a bit responsible for some good discussion.

I actually have, and have had, quite a few pieces of 20 year old HP and TEK equipment.  I currently have an 8457a DMM and quite a bit of TEK TM500 stuff.  I have made some repairs, but in general the reliability is far greater than a lot of modern equipment that I have at work.  I frequently end up bringing one of my instruments to work as it does a better job than some of the equipment we have to use.

In general, the most frequent failure I have seen in the equipment is tantalum caps.  Never an electrolytic and rarely a semi.  My most used scope is still a TEK SC504, 80 MHz analog.  It has suffered 2 dead tantalum caps (PS bypass) in the years I have had it.  Likewise my TEK AFG5101 has also suffered 2 tantalum cap fatalities, but otherwise no issues at all.  I also have a 30+ year old TEK 547.  Needs an overall cal every year or so, but it keeps going and going.  It is more a show piece for me, but still very usable (for those unfamiliar, a mostly tube based with some semis, 5" 50 MHz with plug-in vertical modules.  Weighs about 80 lbs).

As for ROM failures, that seems rare.  I assume that they use EEPROMS, which do have some finite limits on retention life.  As a safeguard, one could unplug and copy them and keep a HEX file or a fresh set of PROMS.

Nice to have lab grade equipment on a beer budget.  While I could afford newer stuff, why spend the money.

Paul
« Last Edit: May 18, 2010, 10:32:26 pm by tecman »
 

Offline saturation

  • Super Contributor
  • ***
  • Posts: 4787
  • Country: us
  • Doveryai, no proveryai
    • NIST
Re: *** SOLD*** HP3456a 6 digit DMM
« Reply #27 on: May 18, 2010, 11:40:42 pm »
Hello tecman,

Again my best thanks for the DVM.  ;D

These pearls of experience are invaluable and thanks for sharing.  My experience with quality is similar with biological and medical equipment, somehow the 1970-1990s produced a range of electronic devices that were indestructible and retired because they were  slow and obsolete rather than ceasing to function.  

Your experience with tantalum cap failures is interesting, since its considered one of the more reliable types today.  However, 40 years ago as it was still new, it was reported to suffer failures akin to electrolytics because of corrosives its in construction.  I guess if we have devices still existing with such caps, we'd expect to see them fail.

http://powerelectronics.com/passive_components_packaging_interconnects/wet-tantalum-capacitors-dscc-93026-0101/

Were those older equipment of yours bought new or bought used?




Nice to see that I was somehow a bit responsible for some good discussion.

I actually have, and have had, quite a few pieces of 20 year old HP and TEK equipment.  I currently have an 8457a DMM and quite a bit of TEK TM500 stuff.  I have made some repairs, but in general the reliability is far greater than a lot of modern equipment that I have at work.  I frequently end up bringing one of my instruments to work as it does a better job than some of the equipment we have to use.

In general, the most frequent failure I have seen in the equipment is tantalum caps.  Never an electrolytic and rarely a semi.  My most used scope is still a TEK SC504, 80 MHz analog.  It has suffered 2 dead tantalum caps (PS bypass) in the years I have had it.  Likewise my TEK AFG5101 has also suffered 2 tantalum cap fatalities, but otherwise no issues at all.  I also have a 30+ year old TEK 547.  Needs an overall cal every year or so, but it keeps going and going.  It is more a show piece for me, but still very usable (for those unfamiliar, a mostly tube based with some semis, 5" 50 MHz with plug-in vertical modules.  Weighs about 80 lbs).

As for ROM failures, that seems rare.  I assume that they use EEPROMS, which do have some finite limits on retention life.  As a safeguard, one could unplug and copy them and keep a HEX file or a fresh set of PROMS.

Nice to have lab grade equipment on a beer budget.  While I could afford newer stuff, why spend the money.

Paul

Best Wishes,

 Saturation
 

alm

  • Guest
Re: *** SOLD*** HP3456a 6 digit DMM
« Reply #28 on: May 19, 2010, 07:00:58 am »
The ROM's aren't EEPROM's, I think they are Mostek mask ROM's. They are known to die after twenty years or so. The contents are available, and there are instructions about alternative EPROM that work (rom_info_rev.txt is the most recent), so replacing them is not a big deal (you just need an EPROM programmer or someone else to program them). I think I even found some usenet posts from Winfield Hill (of Art of Electronics fame) about them ;).

I'm not claiming that transistors and IC's don't have failure modes, but the question is if these are relevant on this timescale. These semiconductors usually don't handle high current and have a huge feature size. Most failures (fortunately) tend to be in simple things like power supplies and connectors, like the already mentioned tantalums. There are some semiconductors with (relatively) high failure rates like the mentioned ROM's and some Tektronix/Maxim IC's in their 2400 series of analog scopes, probably because there was something wrong with that semiconductor process. But then again, people rarely post about their equipment working fine, so you always get a distorted picture (popular equipment seems to break often).

Tantalums from that timespan seem to fail often, I believe those cheap tants were originally intended for consumer audio. It also doesn't help that some companies like Tektronix liked to run things close to the specs, like using 6V tants on a 5V rail.

Modern equipment doesn't always have a great long-term reliability either, think about the crappy electrolytic capacitors leaking after a few years, or the Nvidia bumpgate issue, or tin whiskers due to lead-free processes. So I wouldn't bet on modern day equipment outliving the old stuff (but I wouldn't bet against it either), think of the old stuff as having had a really long burn-in ;). At least the older stuff has schematics available and less custom parts.
 

Offline saturation

  • Super Contributor
  • ***
  • Posts: 4787
  • Country: us
  • Doveryai, no proveryai
    • NIST
Re: *** SOLD*** HP3456a 6 digit DMM
« Reply #29 on: May 19, 2010, 12:39:42 pm »
Thanks Alm.  I have those discussion links, but I thank you for the real links you provide.  For reference to all.  It also has the brief discussion with Hill on his 3456A back in 2005, and Stephan who not only takes the lead, but compiles most of the info.

http://www.electronicspoint.com/hp-3456a-multimeter-roms-gone-bad-t27876.html

The ROM's aren't EEPROM's, I think they are Mostek mask ROM's. They are known to die after twenty years or so. The contents are available, and there are instructions about alternative EPROM that work (rom_info_rev.txt is the most recent), so replacing them is not a big deal (you just need an EPROM programmer or someone else to program them). I think I even found some usenet posts from Winfield Hill (of Art of Electronics fame) about them ;).

I'm not claiming that transistors and IC's don't have failure modes, but the question is if these are relevant on this timescale. These semiconductors usually don't handle high current and have a huge feature size. Most failures (fortunately) tend to be in simple things like power supplies and connectors, like the already mentioned tantalums. There are some semiconductors with (relatively) high failure rates like the mentioned ROM's and some Tektronix/Maxim IC's in their 2400 series of analog scopes, probably because there was something wrong with that semiconductor process. But then again, people rarely post about their equipment working fine, so you always get a distorted picture (popular equipment seems to break often).

Tantalums from that timespan seem to fail often, I believe those cheap tants were originally intended for consumer audio. It also doesn't help that some companies like Tektronix liked to run things close to the specs, like using 6V tants on a 5V rail.

Modern equipment doesn't always have a great long-term reliability either, think about the crappy electrolytic capacitors leaking after a few years, or the Nvidia bumpgate issue, or tin whiskers due to lead-free processes. So I wouldn't bet on modern day equipment outliving the old stuff (but I wouldn't bet against it either), think of the old stuff as having had a really long burn-in ;). At least the older stuff has schematics available and less custom parts.
Best Wishes,

 Saturation
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf