So, what did Zenith do to make their CRT's fail quicker?
 

I think we all know that in the early 1990's, Zenith decided to make their CRT's last only about ~3 years before becoming too dim or failing outright. What I've wondered is exactly how they went about doing this? Did they use less emission materials in their color guns? Did they use under rated color guns (Like color guns meant for a 19 inch TV put into a 27 inch CRT)?

I've heard that weakening the vacuum in a CRT will make it fail quicker. Could this be what they did?

I doubt it was done deliberately!

Once heard that LG (or Goldstar in its original manifestation) sabotaged a batch of their CRTs. Of course, they took over Zenith soon after, and stopped providing buybacks of the modules and other Zenith practices.

You would be amazed at how many people believe manufacturers build things to "fail" at some pre-determined date. You'd think they'd be laughed-off like Elvis sightings, but sadly, no. :no:

Now it's quite possible that somebody said "We don't need this much vacuum" or "This cathode would cost $.0003 less if we made it thinner" etc. But a "goal" of early failure? No.

Mmmmm hmmmm...

I fixed a car door that fell off because the bolt between the two hinges had been designed with the center much thinner then the rest of the bolt. There was no reason I could find for this choice in design, other then eventual planned breakage. A 25 cent bolt from the hardware store fixed that, and it's still working fine. Lord knows how much the dealership would have charged, and they would have of course used another bolt designed to fail after a few years.

More on topic: pre 1992-1993 Zenith CRT's are still for the most part going strong nearly 20 years later, yet those from 1993 onward are weak and dim, if they're still functioning at all.

I wholeheartedly believe modern products are designed to fail after X amount of hours of usage. I've recapped lots of motherboards with caps that decided to fail right around the time when a new upgrade became available (sometimes as early as 6-8 months)

It's tough to figure out what you're talking about, but it sounds like you are describing a "hinge pin", and the reason it was thinner in the center was likely because it was worn out! Is this the $500 T-bird you're always griping about?

As to the CRT failures, it's quite likely they made a production change for one reason or another (either cost, production speed, or new material) and it didn't go so good in the long run. Happens all the time.

Seriously, what kind of sense would it make to purposefully design a CRT that fails after 3-years? Not very likely you'll get a return customer!

You think a conspiracy makes more sense?

No, the hinge pin didn't have wear on it. First off there was nothing to contact that area to cause wear. Secondly, the pin had a light coating of paint, and none of that was worn away.

I think you're being sarcastic, though it's hard to tell.

I also remember reading on the repair FAQ website that someone from Thomson said their CRT's were designed to last around 15,000 hours. With a year being around 8000 hours, one of those 15,000 hour CRT's might last around 6 years if watched for maybe 8 hours a day, and by then of course something new would be out with all kinds of new features.

000

No, I'm not being sarcastic. But who cares? You've got your smoking-gun, er..uh "bolt", as evidence of the plot for unjustified failures. For some reason, your conspiracy theories about things you have no background in, irritates me.

I should get some sleep.

What year was this automobile anyways?

I'm sure someone will soon arrive to explain how Zenith decided it would be in their best interest to design a CRT that fails in three years. Or maybe you'll accept the idea that it was simply a bad design that didn't reveal itself until it was in the field for a while.

My System 3 27" set mfd in 1996 has had as much use as you would expect a primary set of 12+ years to have and is bright as the day it was delivered. I guess it failed to fail.

There's a slight chance that your tube was made by someone else besides Zenith. I seem to remember seeing a couple Zenith's from this period that used the bonded yoke style CRT's like what Thomson/RCA used. Some of the last Zenith CRT sets used Philips CRT's. Or, maybe Zenith "screwed up" and actually made a good tube. It happened once in a blue moon.

LOL

Reminds me of an album by 80s band National Pastime called "Built to Break"

Anyway, again not likely they did this on purpose. But slip-ups do happen when designing a product, and its quite possible that these faulty tubes were indirectly a result of cost cutting.

Cars are a different story though, and a pisspoor example IMO..... Different price point, different use, different MTBF and a hell of a different principle of operation.

Any manufacturer who knowingly markets a crap product that they know will die before it's out of warranty is a thief IMO. This is the main reason why I stopped shopping at Target, Walmart, etc.... its all shit.

I heard somewhere that the aquadag coating inside the tube would flake off and make it's way to the electron gun, causing it to arc/short. As far as the low emission, who knows?

A warning to any "newbies": If you find a '90's Zenith with a shorted voltage regulator, fried resistors, and a blown apart driver transistor in the power supply; just go ahead and trash it. There's a 99% chance that the CRT arced and did it. A shorted CRT can also take out the video driver transistors. I'll never forget the first set I found that suffered from that condition. It was a two year old set with no green. The green driver transistor was leaky. I soldered in a new one and was greeted with a nice picture. After playing it all day without problems, I sold it to a friend. Two weeks later, the set came back to bite me in the butt with a "no green" condition and a blown green driver transistor. Turned out the CRT was the culprit. Back in the '90's, I was getting bad CRT Zenith TV's by the dozens from the local dealer. Many were only 2-3 years old. Heck, I've seen Zenith's right out of the box that looked like the CRT was shot.

I could see a design goof up if the bad CRT's from Zenith stopped shortly after 1992-1993. However, this continued throughout the rest of the 90's at least. Every 1990's Zenith or Zenith made TV I've come across had a weak CRT in it. The one exception was a 27 inch Sentry 2 from 1992. From 1993 onward: bad CRT's, and not just the 27 inch ones. 19 inch CRT's, and even 36 inch CRT's... all weak.

Also, not too long ago I found three JVC TV's from around 2003-2004. not only were the CRT's shot, I couldn't adjust the G2 voltage to brighten the picture very much. The flyback's themselves had something inside them limiting how much the knob could turn. I could turn that knob maybe 1/4 of a turn in either direction.

Finally, A Philips TV from 2005 that i worked on had a "feature" to make it shut down if the screen was too dim. That sure as hell wasn't a cost cutting measure!

EDIT: Also, if a company is trying to save money, why not take a reliable design and stick with it for as long as possible? Why spend the money designing a new chassis and CRT every year? Change the case and update the look/features, but keep the important internal electronics the same.

000

Let's see:

HP print cartridges that stop working after X pages, even if there's still ink in them...

Cars that turn on the check engine light every X miles to 'remind' you to replace the perfectly ok O2 sensor..

Sealed automatic transmissions, so you can't change the fluid and if there's a leak, you can't add any - new GMs are this way...

The infamously marginal timing belt on Hondas...

Lawnmower engines with plastic camshafts...

My other favorite is car parts where there's one REALLY marginal part, but you can't just buy/replace that, you have to buy a whole assembly.

Even nastier - I tried to get a manual for my new car (Mustang). Factory one? Nope - Ford wanted - get this - $10,000 for the manual set.

LMAO! Yeah obviously not, and those bugs made it into other CRT's as the years went by.

Oh, and here's a smoking gun for my conspiracy on products being designed to break: FUNAI! Need I say more?

And don't forget the Sonys that had the AKB blanking circuit that would either blank the video or cause the video to flash when the CRT got weak.

I also had a 2002 JVC "D series" TV with a bad CRT. Then, I had a fairly new 20" RCA Truflat with a toasted CRT. The green was very weak and the blue and red were dead. I think the tube was an LG/Philips. Also ran into an early '00's 19" Orion wal-mart special with a shorted green gun. I was able to swap the tube from another set and save that one.

While I don't think that's a great idea (but I can understand it if I run a large business that needs to schedule maintenance) it's not the same thing as designing a premature failure. Some film cameras re-wind after you take 24 pictures, even though others can squeeze 25 1/2 out of a role. Do I want to take the chance my last picture is screwed up, or know it's done at 24?

VERY old government mandate, since made obsolete by secondary O2 sensors that monitor catalyst efficiency. (How did those get developed when they manufacturers had such a good racket going with the earlier system?)

Stupid idea granted, but becoming quite commonplace on many cars. (Mercedes, Lexus, etc.) Probably done because so many people are adding the incorrect fluids and ruining transmissions. (Just ask Chrysler about all the "bad" transmissions that suddenly started failing when Mr. Lube techs started adding the wrong fluid. It's been happening to everyone). They all still have methods of removing fluid and filter. There are also fluid level inspection ports, but not easily accessed as with a dipstick.

No comment on these related issues. :D

Who stocks parts down to a component level, and when has this ever been commonplace? If a power window motor is supplied to Mercedes by Bosch, do you expect the dealer to carry the internal nylon gear, or complete motors? Should Sony carry individual flyback windings? After all, it only takes ONE bad one to ruin a part.

You didn't say what year, so I just went with the "new" body style. $65 BIN

http://cgi.ebay.com/ebaymotors/2005-...spagenameZWDVW

I was rather surprised to find they still offered a print version myself. Most are CD-ROM now, and I found that version for $14.99 BIN.

I realize that by being realistic and not joining the "I hate xyz" party, nobody like having holes shot in their conspiracy theories. There certainly are a lot of crappy designs out there, and attempted upgrades (for either the manufacturer or buyer) often have the opposite effect. However, this anti-industry sentiment is changing the western-world from a progress-oriented nation of innovators that graduates engineers, (and invents things like color TV) to a bunch of whiney saps that sit around and point fingers at each others cottage-industry of conspiracy.

I've made my point.

As far as the bolt.. thinner means less material.. multiply that buy hundreds of thousands of bolts, and you've got a substantial savings. It also could have cut the cost of machining because of the design...

Concerning the motherboards with bad caps. This is a world wide known problem. At one point, a recipe for the goo they fill them with was stolen from a company and many other companies started to use this recipe.. what they didn't know is that an ingredient was left out of the recipe, causing most of the caps made with this recipe to fail... Also, many of these caps that failed were counterfeits... The computer industry was one of the hardest hit by this, although other industries were too

Helps to know the history of things, and understand how manufacturing and business works before jumping off the bridge..

000

I know all about the history of bad caps. i should have mentioned that LONG after all this was revealed, the bad caps were still being used, and are probably still being used in various designs. The company knows the caps are going to fail, yet they still use them.

While contemptable, that's still not "designed to fail". Designed to fail would be a line of code that shuts everything down after X number of start-ups.

Amen. :thmbsp:

Mmm, like certain pieces of software that after X amount of days, they shut down and prompt you to upgrade.

MS hasn't tried this yet with Windows, but their more subtle lifecycle policy was put into place simply because software code doesn't wear out, and can be repaired just by inserting the CD and reinstalling.

And honestly: what company WOULDN'T want you to buy a new whirlygig after the old one stops working?

MRX, I hate to jump into this, but give me an actual example of software meant to fail.

The only software that does this is free demos of commercial software or unactivated versions of Windows.

Also the caps thing... most boards that have shitty caps these days are ECS boards, and those have been known shit since the stone age.. All the good manufacturers have learned their lesson and use good caps (Samxon, Nichicon, Rubycon, Nippon Chemicon, Matsushita).

Software is a different matter entirely. Those programs that stop working after X number of uses are akin to "trial size" soaps.

The point being made is that just becuase something is a piece of crap (like a Funai) it doesn't mean it was designed to fail. It would actually require a fairly high level of engineering to design a product to fail just outside of warranty, but last long enough not to damage a reputation... More than I would think a company like Funai capable of doing.

I hesitiate to mention it, but it's like those granola-eaters who think GM conspired to buy up all the streetcars/trolleys so people would have to buy private cars. (And please don't bother showing me websites that say it's true... I can find holocaust denial sites too.)

Do you think the average person needs to be "pushed" to drive a private car? You like standing at the bustop in the rain? Riding next to crazy people? Moving on somebody else's schedule? As it is, we subsidize public transport now just to keep it cheap enough for people to use it.

Everybody wants to jump to conclusions, or find the bogey-man in the closet. Hey, Zenith 1993-era screwed up on some part of the manufacturing process where they should have known better on. Then they figured it out and fixed it, but it was too late... Damage done, nail in the coffin.

Nobody ran out to buy another Zenith after the first one failed, they in fact AVOIDED them! I know that to be true because my parents bought my grandparents a 1993 27" Zenith based on the excellent performace of their 1990 27" Zenith (which is still my main TV). When the newer set died, Zenith was off the shopping list.

The dim Zenith CRTs we saw also took a long time to brighten, and even longer for white balance to stabilize. It looked like low heater voltage, but I would guess that something bad happened to make cathode emissions non-linear, like a warped screen grid. There were a batch of bad JVC 26" crts one year, all with shorting guns, and all NAP oem. Oddly, the Magnavox sets using the same crts rarely failed. That always seemed fishy to me.

Around this time frame, CRT manufacturers were trying to reduce energy consumption by lowering the peak temperatures and reducing the length of exhaust and screenbake cycles. In our experiments, life test suffered and we never cut back on our heat cycles during production. I suspect Zenith and some others did and paid the price.

Companies spend lots of money every year researching and testing potential new designs. Getting a product to fail just outside of its warrenty isn't an exact science, but you can't tell me they don't design their stuff to eventually fail.

I'm working on a convergence board right now from a Philips PTV835. It had several resistors right next to the convergence IC's, which of course get hot. These resistors were a brown color and made of a different material then the rest of the resistors in the TV. They had of course failed.

Were the resistors so close to the IC's because of lack of room? No. There's a ridiculous amount of empty space on this convergence board. It's bigger then it needs to be, yet those resistors were crammed right next to the hot IC's.

He's right, everything is designed to break now days. I had some of those lawnmower engines. Here is what they said on the top: 5.5 Hp Commercial grade. These were made by Briggs & Stratton. Cam lobes made of plastic. The tappets and valve stems are also thinner than a pencil. They used to be as large or larger even on a little 3hp. Every time I get one of these, the valves are shot and there is no compression. Pure garbage. The old Briggs engines are built like tanks. They just don't want smart people to fix things anymore, they want us to be consumers and nothing more, at the mercy of shops and companies raping us for money with little we can do about it. That is why I'm vintage all the way. I'm not playing their games. I work too damn hard for what money I get.

I found my Snapper lawnmower in the garbage. all it needed was the pull string spring lubricated.

I also have a John Deere push mower from 2006 that has much more plastic, a thinner pull cord, and a hard to find oil drain plug (it's under the mower, easily hidden by grass buildup). I had to change the spark plug, and fix the throttle cable on it. The damn thing wasn't even 2 years old when I found it!

My snapper mower is probably a good 20+ years old, and the only maintainence I do to it is change the oil regularly, which is easier because the drain plug is easy to spot. It hasn't needed a new spark plug yet either.

My mother had a poor experience with Delta Airlines in 1963, and she would never fly on them again, and she lived until 2005.

My Zenith Sentry 2 19" table set is 14 years old and still has the original CRT. As the previous poster described, the tube in my set is as strong and bright as when I got the TV. I also have a 9-year-old RCA CTC185A7 XL-100, with the original CRT and a fantastic picture. The Sentry 2 is in my bedroom and doesn't get much use (was my main watcher from 1995-1999, then I bought the RCA when I moved here in '99), but I use the RCA most of the time, mostly these days for watching the news and DVDs/VHS videos.

I'm almost convinced that I got a good CRT in my Zenith purely by the luck of the draw, considering all the problems Zenith had with CRTs in their televisions from 1990 on. However, I'm not surprised my RCA's CRT is still good and still makes a picture as nice and sharp as you please. The failure mode of most RCA TVs of the early nineties was not, as a rule, the CRT; rather, the onboard tuner becoming ungrounded (through bad solder joints) and bombarding the jungle IC (EEPROM) with noise and ruining it in short order was a major problem until the CTC203 and its successors, as in these sets the tuner is mounted separately from the main board. However, a friend of mine told me his parents had an RCA Guide Plus 25" TV in which the CRT failed after just two years. They bought a new set, same screen size, that worked right out of the box and is still working today, some five-plus years later; no CRT problems or chassis faults. An interesting side note: This TV actually fell off its stand several years ago, but again is still working; the CRT shadow mask apparently wasn't bent when the set hit the floor. I had the same experience last year, with my RCA XL-100 CTC185. However, I was able to eliminate the color splotches in the picture by running a magnet from an old loudspeaker around the screen.

The Zenith we all knew and loved overbuilt its sets compared to the competition. By the 80s TV sets were becoming a commodity. Why buy the Zenith when the store down the street has a FlungDung that does the same thing: it has a decent color picture and the same basic features, yet costs $100-200 less? Zenith had to change; it had to cut costs. It moved production to Mexico. It lost ground on R&D versus the competition. At some point, faced with an uncertain future, they had to cut more corners. From what I have read, the '93+ crts were designed to be just as good, or even better, but be cheaper to make. Even if the crts had been good, those sets were far from the best on the market. From what I've seen an RCA/GE from that era was a vastly better set. The sad thing is that Zenith was probably the most common brand being sold by independent dealers. I've spoken with several guys who sold only Zenith in later years because of easy parts availablity and the fact that they catered to the small shops. All those little guys then had to deal with unhappy customers.

I really don't think there was any malice on Zenith's part. In the situation they were in c.1992 the only other choice may have been to close the plant and buy all their tubes elsewhere.

Oh, why is there crap like plastic camshafts and FlungDung TV sets? 'cause that is what people buy. The next time you're in WallyWorld, take a look at the lawn mowers. Now, had did they get them that cheap? Compare the price of a no-frills push mower to the cost of a new 3.5hp motor out of a catalog. The money is in volume; the volume is in cheap. This is not new...it is older than any of us having this conversation.

So, the answers I've gotten range from LG sabotaging their CRT's, to Zenith cutting corners and trying to make a cheaper decent CRT but failing miserably.

Any other theroies, or better yet maybe someone here worked at Zenith during the 90's, or knows somebody who knows somebody who knows somebody who worked there during the bad CRT era.

Anybody remember the notorious bad solder joints between boards in late 80's vintage RCA sets? I was the CE at a hotel that had 145 of these sets, all manufactured in 1989. (I forget the model #, silver XL100 set with analog AM/FM radio). Anyways, right about the end of 92 and into 93 I spent plenty of days fixing these darn sets - which never really had a single component failure that I can remember - just bad solder joints throughout. But with that experience, I have never purchased an RCA or GE set either for work or personally since.

The next facility I took care of had 85 Zenith 25" Concierge sets m'fd in 1995, and I rarely had a problem with those for the two and half years I was there. Sometimes the Smartcards would need to be reinstalled (sorta like a reboot), but that's it.

The place I'm at now had all 1996 vintage mexican-made Zenith HealthView sets, and those were problematic - either bad modules or the CRT's would go south, sometimes both. But those had high hours. Most of those are gone now, but we still have a dozen or so of those old sets still in daily use with the original CRT's. Couldn't even guess how many hours are on 'em. I spec'd out newer Philips 19" commercial TV's, and we purchased about 15 of them several years back. Those are all going strong with great pictures and no servicing req'd. The rest are all just LG/Zenith HealthView's, same exact model that we've used all along. The bean counters insist we keep buying them. The newer ones are hit & miss, a few have died outright within months, I've seen two with bad guns within a year, but most are still OK after a few years of service.

I remember the late '80's RCA's with the MTT tuner module that always had bad solder connections on the plugs and the wirewrap stakes. These would have been in late production CTC120, CTC130, and CTC136 chassis sets. The older RCA's with the MSC tuner controller and MST tuner module suffered from the same problem. The solder problems with RCA really took off with the introduction of the CTC175/76/77 chassis in '92 or '93 and continued thru the later production CTC203's when RCA finally got sense enough to use a seperate tuner instead of their lousy "tuner on board" design. Those sets are usually good after the tuner grounds are resoldered. The main component failures I've experienced were bad eeproms (due to bad connections), shorted HOT, defective regulator IC and shorted B+ rectifier, and the occasional bad flyback. Once RCA started using a real tuner again, their flybacks started going south way too soon! Go figure!

One of our local hospitals had those Zenith healthview sets like you mention. I wound up with a few of them that had, of course, bad CRT's. Years ago, another hospital had a bunch of mid '70's 19" Sylvania's with motorized tuning (heavy as lead and probably their best sets). Those were replaced in the late '80's by 20" Magnavox cable ready sets. Those sets were recently replaced by Philips BPC sets. I wonder if they'll last 20 years like the previous Magnavox sets.

I'm a little puzzled..........
 

Unless I missed something, everyone in this discussion has only talked about Zenith CRT problems around 1992-'93. By 1990 I was seeing Zenith tubes fail faster than I could haul the carcasses away, starting with sets from '87 and '88. Lots of H-K shorts, and lousy emission.

RE: CTC120-136 chassis. I got in the habit of resoldering those wire wrap stakes on every one of those sets, no matter what I was asked to fix. Kept the callbacks down to near zero.

Re: CTC175+ tuner-on-board: I hated it because it was a stupid design, not having wires to backup those tabs on the shield to tie grounds together, AND I loved it because I have earned tens of thousands of dollars fixing them. At one time I had a running count going on how many I had fixed. I lost track at almost 600 units, but I was still fixing those then so the total is higher than that. ( I still see one from time to time)
At the Thomson training session that covered those (spring of '93 I think) several of us went to the FSM and expressed our concern about that design during the lunch break. We were assured that the engineering guys had tested the design and the grounds would not fail as they had been doing in Zenith and other tuners. AS he said that , I had the feeling that he didn't really believe it, but he had to say it.

Plastic camshafts in lawnmowers??!!! I was not aware of that, but it sure explains a lot! I have seen plastic pistons in brake calipers. Wont use them again. I've had 2 of them warp and bind in the bore. Sure made the van steer funny!

Re: Sony blanking until the tube is warmed up. I recall Sony did issue a mod for those sets to reduce the blanking sensitivity. I think late production sets came with it from the factory but early models were extra touchy and changing a resistor or two helped.

OK. I'm done now.

I too remember a fair amount of late '80's-early '90's Zenith tubes being bad; but, the problem really took off around '93. Really, here are my experiences with Zenith CRT's:

1. Delta gun tubes from the '70's almost never went bad. Even to this day, they are still very watchable.

2. The first inline tri-pot tubes used with the system 3 chassis were not as good. The 13", 17", and 19" held up pretty good but I've seen plenty of weak 23"/25" ones.

3. Same story on the COTY (?) tubes from the early '80's thru the early '90's.

4. And, we already know about the early '90's and up.