Schematics and knowledge sharing thoughts

[RoadrunnerOZ]

Yeah a lot of the board swap repairs back in the ‘80s and ‘90s relied on sending the faulty board back as exchange (warranty) or paying the price for a new replacement (non warranty) - some had reduced cost to supply with an exchange board, as the boards could be repaired. For some console repairs I had repair test jigs supplied by the manufacturer which had a power supply, edge connectors and test insertion points on a breakout panel. This started many years ago.

 

[vintageampfixer]

Yeah a lot of the board swap repairs back in the ‘80s and ‘90s relied on sending the faulty board back as exchange (warranty) or paying the price for a new replacement (non warranty) - some had reduced cost to supply with an exchange board, as the boards could be repaired. For some console repairs I had repair test jigs supplied by the manufacturer which had a power supply, edge connectors and test insertion points on a breakout panel. This started many years ago.

it's much the same process now ...

 

[RoadrunnerOZ]

Except for a few brands which I won’t name that require the whole machine to be returned to the supplier, they have representation in only one city in the whole country and no outlying service available - cost to send and return the product is on the end user which is pretty expensive for a warranty service and leads to long delays in getting the gear back and on the road. This is a big country (Perth to Melbourne for example is 3400Km, to Sydney 3900Km) with a relatively small population and I guess doesn’t get the same service support you’d get in Europe or the States. I used to manage a pro-audio store for about 10 years and we had to have loan/hire gear that musos could use while waiting for their gear to be repaired if it had to go to another city for warranty repairs. Some importers only have a container come in every 6 to 8 weeks or when it’s full if they don’t have the spares in stock and won’t do air import unless you pay for it.

 

[JohnRoberts]

I have been up to my neck in this game for most of my career and never designed a SKU to fail on purpose. I will concede that I have been out of the large company trenches for decades, but only shut down my last business about 4 years ago. FWIW that last SKU I designed had a three year warranty, and in the 3 years after I stopped selling them I got exactly zero warranty claims. I guess I screwed up and made the design too robust.

From a distance I can see aspects of modern manufacturing that make easy servicing difficult. It's hard for a vendor to support repair parts or sub assemblies when the production is done on the other side of the world in one huge batch and the next generation SKU may use newer completely different technology.

The only constant in the world is that it's always changing.

JR

 

[TimG]

That’s kind of cool you had actual data on the failures (zero) of your design project.

When I worked in TV news libraries I always wanted to know how many lawsuit claims my group had gotten, versus the “other group” for using 3rd Part Material, but the attorneys with the data weren’t always willing to share, making it more difficult to improve, iteratively.

 

[jp8]

Companies don't want the product you bought from them to be repaired
Companies want you to ditch the failed product and buy from them a new one, or the new model, or version MKII
Companies don't do and don't want to do any longer products that are made to last a lifetime

I don't think you can make this a generic statement. What do you base this on? This certainly doesn't apply to the product group of my company that I help develop. We're always proud to receive letters from happy customers (really, we do get them!) about the lifetime of the products we develop, manufacture and sell.

And if devices are sent in for warramty or repair, yes, we do often ditch the device. Especially the cheaper ones, because spending $50-$100 on fault finding and swapping out that $0.01 part makes no sense. We just swap out modules or complete devices.

Releasing the Schematics would make it easier for consumers to find they designed a product to fail, would make it easy to repair it and to share how to solve the weak points, and if all that happens they would not sell you a new unit

I don't think you can reliably predict lifetime from a schematic. And if you can to a certain extent, it's not always easy, or it's even impossible, to modify and improve the circuit on the given PCBA and in the given volume etc.

Planned Obsolescence is not a conspiracy theory it's very real and implemented in the majority of electronic products at the present.

Majority...? I take this as an opinion, rather than a fact. Unless you can point me to a source which has done some decent research on this.

Although there could be companies that design in Planned Obsolence ( which I translate to design for defined, short lifetime), it would mean that you would actually have to do extensive simulations and life testing to prove the planned short lifetime. After all, you don't want to sell products that fail too soon, as JohnRoberts already pointed out. Or that actually prove to be too good. Anyway, such extensive life testing is rather expensive and time consuming and I don't expect this is done a lot on cheap consumer goods. Or on expensive devices of which not many will be sold. I think short lifetime/high failure rate is more often a result from how products were developed, rather than being it planned for. Small R&D budgets, short development times without testing and iteration loops, ignorant developers making stupid design flaws, spending money on bells and whistles rather than quality etc. Just my opinion based on 40 years of hardware design experience, hardware repair and reverse engineering of many products Do not take as a fact...

Jan

 

[JohnRoberts]

That’s kind of cool you had actual data on the failures (zero) of your design project.

When I worked in TV news libraries I always wanted to know how many lawsuit claims my group had gotten, versus the “other group” for using 3rd Part Material, but the attorneys with the data weren’t always willing to share, making it more difficult to improve, iteratively.

Some people complain about my Peavey stories, but back last century while I was working there we decided to extend our warranty from 3 years to 5 years for competitive marketing reasons. We did a rigorous review of in-warranty and out of warranty repairs. Long story short, it was a no brainer and we extended the warranty 2 more years with no significant problems. Most failures are "infant" failures and occur relatively soon in a products life. Once they survive infant failure modes, they are usually good for several years if not abused.

During the investigation I found one modest analog power amplifier that had higher than expected field failures for that particular SKU's sales volume. It was not on our radar because it was a low volume seller and the service department knew how to fix the few that they saw, so they never complained. I asked the head of analog engineering to review that amp's field failures and he found a minor design flaw, one transistor had a marginal voltage rating. He wrote the engineering change order to use a higher voltage part and those field failures stopped. I'm sure if this was a higher volume SKU, the flaw would have been found sooner (squeaky wheel gets the oil).

JR

 

[brucega]

I bought a used Peavey mixer in the early '80s, 12 channel, transformer mic inputs, balanced outs, built into a road case. It was still working last year, but I gutted it. Was hoping to get the specs on the mic transformers.

I loved that mixer, even though it was a tank to lug out to jobs. Much respect!

 

[Whoops]

But why would you buy a new product from the same company whose previous product failed before it should have ?

JR

Many reasons John,
But one of them could be because the consumer liked the product in the first place…
… liked it’s features, liked it’s price, liked to use it…

But Planned obsolescence is so deep rooted into society and economics that the majority of people nowadays when a product fails after 5 years they think it’s normal.
Common people just say “well it failed because it was already time to buy a new unit”. And also the majority of people don’t think about repairing it all, they just bin it and buy a new one.
(I’m not talking exclusively about audio electronics, but electronic products in general)

 

[JohnRoberts]

Many reasons John,
But one of them could be because the consumer liked the product in the first place…
… liked it’s features, liked it’s price, liked to use it…

nobody likes it when a product fails (AFAIK). I have been paying attention to this stuff for several decades. I recall reading an article last century about how customers were more likely to be repeat customers if they had a failure and a good customer service experience. I remembered that because it did not seem logical to me.

But Planned obsolescence is so deep rooted into society and economics that the majority of people nowadays when a product fails after 5 years they think it’s normal.
Common people just say “well it failed because it was already time to buy a new unit”. And also the majority of people don’t think about repairing it all, they just bin it and buy a new one.
(I’m not talking exclusively about audio electronics, but electronic products in general)

I am not aware of this deep rooted cultural "new normal". I don't know of an engineering discipline even loosely related to planned failure. Most engineering efforts I am aware of is trying to insure "extended" reliability.

Several things have impacted modern manufacturing. Increased labor and transportation costs have dramatically flipped the calculus of repairing SKUs. I shared this story years ago. I bought a big dehumidifier that failed out of the box and the manufacturer didn't want it back. They just had me scrape the serial number off it and they shipped me a new one (I ended up salvaging a run cap out of it when the second unit failed).

JR

PS: I have a related complaint about the sacrificial anode in my hot water heaters. These are supposed to be replaced every several years to manage internal oxidation. I was unable to remove the anode in my heater. I hired my plumber and he couldn't get it out. After several years I suspect many homeowners just give up and buy a new hot water heater... (I didn't).

 

[RoadrunnerOZ]

To build a product with Planned Obsolescence of say 5 years the manufacturer would have to first design & build multiple prototype versions of the same product as well as having multiples of each version and run these under test for five years to see which version(s) would fail at the five year mark. Then set up production based on known obsolescence time and finally release the product. It doesn’t sound likely to me. If you have a device with 5000 components and tried to calculate the collective sum failure time based on each individual component’s stated failure and tolerance ratings (overvoltage/reverse voltage/overtemp/current/wattage etc.) and the operational temperature and mechanical stresses expected at each of the device components you would need some pretty serious computing just for planning a failure time.
It seems that it’s more likely accidental failure time and if too many fail within the warranty period the manufacturer modifies production design accordingly.
Under Australian Consumer Law the warranty does not limit the expected useful lifetime to just the warranty period - the goods must be of acceptable durability to provide a reasonable lifetime under normal operating conditions and these terms and conditions of sale apply to all products sold or manufactured for sale here. If there were a planned obsolescence time period the manufacturer and the sales outlet would be obliged to state this under the warranty terms and conditions and make this known to the customer at the time of purchase.

 

[Brian Roth]

@RoadrunnerOZ I may be mistaken, but I believe in the USA that once the stated warranty period has elapsed, the consumer has no further recourse/claim against the manufacturer. And as others have mentioned, we are so acclimated to failure that everyone accepts it as a fact of life. "Oh well, that $1000 TV set died shortly after the 2 year warranty expired...must be time to buy a new one".

I will mention one thing from my direct experience. I currently maintain a fleet of eleven Ampex ATR-100 tape machines. The production ran from approx. 1976 to maybe 1984. With that many machines being 40+ years old, I'm pleased to report that failures are relatively few (although I have to keep on top of them since we have so many machines that the odds of a failure are much higher than a typical studio with a single machine). Things like a random 74xx TTL chip, a few PSU bypass caps, one large 'lytic "can" in a PSU recently,,,,and VU meter bulbs! <g>

Ampex supplied large 3" thick 3-ring binders with each machine. In there are complete schematics (most fold out as 11x 17 pages), parts lists, mechanical drawings and theory of operation.

I don't know what the warranty period was (1 year?) but an ex-Ampex engineer on the Ampex Mailing List stated their design goal was a ten year lifespan. Why that? Because that was the tax depreciation period for corporations at the time.

Of course....they were expensive machines when new!

Good luck buying ANYTHING these days that will last 40+ years, regardless of price.

Bri

 

[RoadrunnerOZ]

Yes indeed - it seems like we can’t afford to build machines like that any more as no one could afford or want to buy them. I remember when a new console could cost many times the price of a house and a new house would cost $20K - $30K - around the cost of a good 24Tk tape machine here. The build quality was certainly a lot better than what we get today - it seems that design is based on minimising time and cost to produce and not on maximising quality - meeting expectations for on paper performance specs to compete with other brands.

 

[Jazid]

Although there could be companies that design in Planned Obsolence ( which I translate to design for defined, short lifetime), it would mean that you would actually have to do extensive simulations and life testing to prove the planned short lifetime. After all, you don't want to sell products that fail too soon, as JohnRoberts already pointed out. Or that actually prove to be too good.

There certainly are companies that cynically design and hard wire obsolescence into their products.

Not audio, but a well known Korean computer company includes a sacrificial resistor into the imaging unit of its cheaper printers. These typically go to households and see modest printing runs. The run ratchets up until at approx 5k the resistor fails and the printer reports that you need a new imaging unit (for a bit more money than a new printer costs). Hey presto, new printer please! Or replace the resistor and get a miracle "new" imaging unit -they seem to work fine for ages afterwards. This only works if the original resistor failed open. Some fail short. Then you need a new printer anyway. Not an expensive scam to implement, a few cents, but quite a profitable one.

Presumably it allows the company to not inventorise significant quantities of spare drums, belts &c.

 

[saulpickett]

Hi I would just like to add to this discussion and say ... I would venture to guess that most of what we consider to be "Classic" is simply gear that was able to stick around and stand the test of time.... what good is an old blackface fender bassman? Who knows, but it probably still works... and therefore most people have some fond association with those amps (My point is that fenders stuck around, and kept sticking around.) I suspect this is a large part of classic audio gear. Once the gear gets to be 10 years old and is repaired a couple times or whatever, now people have a more intimate understanding and appreciation for it.