What happens if you run 40V next to LVDS in a 0.4mm connector - Page 1
Forum section: electronics / general

author: blueskull
author_rank: Unknown
timestamp: December 08, 2018, 04:57:41 am
content: Well, here's the video. This is how Apple designs their $3000 gears.Who the hell came up with the idea to run 40V right next to eDP in a 0.35mm/0.4mm pitch mezzanine connector in the first place?The eDP is a 400mV AC-coupled LVDS-like signal.Now, here are the options:Adding a single ground barrier pin can solve this issue.Increasing the DC-blocking cap voltage to 50V cal solve this.Adding a clamp diode can solve this, better if the clamp also pulls down ENA pin of the backlight boost chip with an NPN.And voila, they didn't do anything.

author: TerraHertz
author_rank: Super Contributor
timestamp: December 08, 2018, 09:47:10 pm
content: Not to mention using just one tiny pin for what is apparently a fairly high current circuit. May be fine for a while so long as the mating surfaces are nice clean gold plating. But not once it gets some dirt or wears through the very thin gold plating. Hence all the heating burning melting effects (and leaking electrons to adjacent pins.)I wonder of this kind of design error is due to deliberate planned obsolescence thinking, or an effect of SJW-nutcases in engineering being simply incompetent?

author: Halcyon
author_rank: Unknown
timestamp: December 08, 2018, 10:18:32 pm
content: I almost expect this kind of thing from Apple these days. Year after year, model after model, Apple churns out some overpriced, half-baked iPad, iPhone or MacBook and there is always some issue. Apple is a prime example of how money doesn't equal quality and goes against the "you get what you pay for" mentality.Once upon a time I would have said I didn't mind Apple hardware but those days are long gone.

author: tooki
author_rank: Super Contributor
timestamp: December 09, 2018, 02:22:19 am
content: Suppose Rossman fixes this issue on, I dunno, 200 such machines. That's out of how many millions of units sold? His videos and claims are not even the tiniest bit representative of the actual failure rate. There's no actual evidence whatsoever of Apple devices having an above-average failure rate, if anything, it's the contrary.

author: wraper
author_rank: Unknown
timestamp: December 09, 2018, 02:52:03 am
content: Quote from: tooki on December 09, 2018, 02:22:19 amHe's not the only one man in the repair business. If he sees a lot of laptops with the same issue, so do other repair businesses too.

author: wraper
author_rank: Unknown
timestamp: December 09, 2018, 03:02:28 am
content: Quote from: tooki on December 09, 2018, 02:22:19 amContrary such as multiple repair extension programs of their crap? Usually made after several years after purchase on conditions that most affected customers will miss that deal? BTW, they are churning out very small number of models compared to other manufacturers. Who BTW have much less money for R&D not only for one model but in a whole as well. So apple design flaws have even less excuse IMO.

author: Mr. Scram
author_rank: Super Contributor
timestamp: December 09, 2018, 03:06:32 am
content: Quote from: tooki on December 09, 2018, 02:22:19 amCan you supply this evidence?

author: wraper
author_rank: Unknown
timestamp: December 09, 2018, 03:19:11 am
content: How about their chargers with 1.5 star rating?https://www.apple.com/shop/product/MD506LL/A/apple-85w-magsafe-2-power-adapter-for-macbook-pro-with-retina-displayHow about their cables which usually don't last even a year of normal everyday use, often not even 6 months. And this continuing for a decade. When virtually any other company don't have any issues with cables.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 09, 2018, 03:42:47 am
content: Quote from: TerraHertz on December 08, 2018, 09:47:10 pmIt's been around for ages. IIRC, the de-facto S100 card edge standard placed 15V (AC or DC?) right beside a critical control line, or logic supply or something. Shorts due to misaligned connectors or hot-plugging were a thing...Or it's like the old joke:QuotePersonally, I make sure to leave a buffer pin around very different lines, like high voltage supply versus logic level signal. But not everyone has that foresight, or the experience that this kind of thing can happen.And yeah, it's still perfectly 100% absolutely fine in the absence of contamination. This shit only happens when something gets spilled on it*. And yeah, confirmation bias is hard to avoid when you only see the worst of the worst in your shop. The actual maintenance engineers, responsible for addressing the most common complaints frommillionsof units in the wild, are going to put quite a low priority on the more unusual and strange incidents. (And probably a low priority on any kind of liquid damage -- that's literally not their fault!)*Or when it gets dusty and condensing humidity occurs. Same thing, but not as obvious.Tim

author: Halcyon
author_rank: Unknown
timestamp: December 09, 2018, 04:09:50 am
content: Quote from: tooki on December 09, 2018, 02:22:19 amWhich stats have you been looking at Tooki? While Apple is considered a "premium brand", their build quality and robustness is anything but. Everything from bending phones, failing components, cracking chassis', poor soldering and stupid design decisions, it's no wonder Apple users replace their products every year or two.One just needs to look at the list of recalls or what Apple call "extended repair status" on their products and that's just what Apple are willing/forced to admit to.I've worked on pretty much every manufacturer's devices for the past 20 years and personally, I put Apple down there with Acer and consumer-grade HP and Dell products. On any given week, I probably work with 40-50% Apple products, and a significant portion of those have some kind of issue that isn't obviously caused by liquid or drop damage. I have a MacBook Pro on my desk right now that just decided it didn't want 2 USB ports any more as one just refuses to work.Then there are the endless issues with breaking accessories, especially charger and data cables. If Apple charged a fair price for what a reasonable consumer would pay to have a device that lasts under 5 years, then fine, no problems. But you pay a premium price tag you expect premium quality products and service. There is absolutely no reason why a decent quality laptop shouldn't last 10+ years.

author: tooki
author_rank: Super Contributor
timestamp: December 10, 2018, 12:42:46 pm
content: Quote from: wraper on December 09, 2018, 02:52:03 amThere are very, very, very few places doing component-level repairs on these things. So even if there are, say, 100 such companies worldwide doing such repairsregularly(which I think is probably about 80-90 more than there actually are), that's 20,000 units out of literally millions upon millions upon millions sold! It'sstilla vanishingly small failure rate.Quote from: Mr. Scram on December 09, 2018, 03:06:32 amEasily:http://fortune.com/2018/03/12/apple-macbooks-most-reliable/Even Apple'sworstis better than the competition:https://appleinsider.com/articles/18/07/12/study-iphone-6-has-highest-failure-rate-among-iphones----but-samsungs-rate-is-higherDoes this mean there's no room for improvement? Of course not. But people have to remember that bashing on Apple gets clicks, so content authors (like Rossmann) hype up the failures.The big exception, where I agree with everyone here, is the cables. I've written about this before on other discussions, e.g.https://www.eevblog.com/forum/chat/teen-dead-after-rolling-on-to-iphone-cable-in-her-sleep/msg1355140/#msg1355140I don't know what Apple's magic PVC-free insulation is, but it sucks. I do not buy Apple cables, but instead on high-quality third-party.Quote from: Halcyon on December 09, 2018, 04:09:50 amExcept they don't. Apple devices tend to last far longer than industry average. A recent calculationestimates an average life of 4.25 years.There is NO evidence of systematic problems with any of those things you list. (Yeah, you can bend a thin phone, cuz physics. Maybe don't sit on it in your tight jeans.) Poor soldering? Seriously, Apple's boards areimmaculate.Quote from: Halcyon on December 09, 2018, 04:09:50 amOverall industry stats disagree. ::shrug::Quote from: Halcyon on December 09, 2018, 04:09:50 amThe cables suck. The chargers themselves are excellent. (I am happy that all the new MacBooks that charge with USB-C also use chargers without permanently attached cables.)What other accessories have "endless issues"? It seems to me it's JUST the cables that suck.Quote from: Halcyon on December 09, 2018, 04:09:50 amApple's service, even with its occasional warts, is still second to none. Even with the occasional slip to second place, Apple tends to be at number one for year after year after year. E.g.https://www.laptopmag.com/articles/apple-tech-supportQuote from: Halcyon on December 09, 2018, 04:09:50 amIgnoring the fact that nobody actually wants to use a 10+ year old computer (heck, nobody even wants to use a 6 year old one, which is why nobody designs them with a 10+ year durability), IMHO that depends more than anything on the user. Other than wearing out batteries after hundreds and hundreds of cycles, I've never worn out a laptop. My PowerBook 3G from 2000 still works great. My MacBook from 2008 is fine, too. My current MacBook Air is from 2012. (I sold my 2003 PowerBook G4 in 2008, so I don't know its outcome, but it had already made it to 5 years.) My primary computer right now, by the way, is a 2008 Mac Pro.Working as a computer tech, I saw some people take laptops and other portable gadgets from new to falling apart in less than a year. I honestly don't know how they do it. (For example, years ago my sister and I bought matching Walkmans, nice ones with metal cases. Mine still works today, and looks lightly used. My sister's was dented and messed up in a year!)Are Apple laptops as mechanically durable as the best ThinkPads, or the Panasonic ToughBook lines? No. But as long as you don't drop them and dent the aluminum, or drown them in liquid, they tend to last.

author: amyk
author_rank: Super Contributor
timestamp: December 10, 2018, 01:02:35 pm
content: The history of Apple is filled with questionable design choices. Starting from a16-year clock on the Lisa, to mouses with a single button, cables without strain reliefs, non-removable batteries,severely undersized laptop AC adapters, ultra-fragile keyboards, etc. It's form before function, nothing more than an impractical fashion statement.

author: tooki
author_rank: Super Contributor
timestamp: December 10, 2018, 02:39:09 pm
content: Quote from: amyk on December 10, 2018, 01:02:35 pmI agree that some decisions are questionable. But the ones you list are not among them.Quote from: amyk on December 10, 2018, 01:02:35 pmThere was no reason to expect that computers would be used for decades. PCs of the era have similar limitations.Quote from: amyk on December 10, 2018, 01:02:35 pmThis was an unquestionablygooddecision, in that it forces developers to never hide any commands in a right-click menu only. (This is why single-button is still the default mode on Mac pointing devices, even though they all support right-click and multitouch now.) You also must understand that in early user testing, users had trouble remembering which button to use. It's easy now to look back and say "how dumb", but we now grow up using these things. In the early 80s when they were designing the Lisa, no consumers had ever seen a mouse.Quote from: amyk on December 10, 2018, 01:02:35 pmHow many more times do I have to repeat that I agree about Apple's cables?Quote from: amyk on December 10, 2018, 01:02:35 pmThose have pros and cons, just like removable batteries do. (In fact, the next issue would have been prevented by a non-removable battery…)I like removable batteriesin theory, but the fact is, the overwhelming majority of customersnever, everuse a second battery (as in, swapping back and forth). And for battery replacement (as in, when the battery has failed so you need a new one), Apple's battery replacement prices (with installation) are exactly the same as the prices were for their removable batteries.So with removable batteries having surprisingly few advantages for most users, then it makes sense to allow the advantages of non-removable (reduced weight and girth, easier to implement waterproofing) to win out.Quote from: amyk on December 10, 2018, 01:02:35 pmIn electronics engineering, we often use capacitors to allow peak current draw far in excess of average current draw without having to use oversized power supplies. They just used the battery to accomplish this, instead of requiring a far larger AC adapter, just to enable peak performance in a usage scenario that almost never occurs. (Who uses a laptop without a battery? Heck, they're hard to use like that, since without the weight of the battery, they're often top-heavy. And in those MacBooks, with MagSafe, it's deliberately very easy to unplug the power cord, so running without a battery is inadvisable for that reason alone!) With the battery installed, as is the case 99.9999% of the time, peak performance was always available, whether running on battery or AC.Quote from: amyk on December 10, 2018, 01:02:35 pmThe butterfly keyboard does indeed seem problematic. (We shall see if the revised versions with better seals fare any better.) Beyond that, no real problems with keyboard durability.Quote from: amyk on December 10, 2018, 01:02:35 pmSometimes, yes. (I think Apple could sometimes go back to slightly more function-over-form.) But they're hardly "impractical fashion statements". I am not a fashionista in any way. What I like is stuff thatworks well, and in this, Apple products have worked far better than anything else I've tried. It's not perfect, but it's not the horrors that I experienced with Windows. It's far more "practical" to me to use gear that just works, and lets me focus on my work, not on configuring, maintaining, troubleshooting, or otherwise babying the computer.

author: coppercone2
author_rank: Super Contributor
timestamp: December 10, 2018, 03:17:03 pm
content: Quote from: TerraHertz on December 08, 2018, 09:47:10 pmok, so you are saying the gestapo had good PCB layout practices for some reason?perhaps it does make sense, because they know not to put the aryan brotherhood members by the MS13 cells. Yea. I think I will look at hiring some prison guards

author: Kilrah
author_rank: Unknown
timestamp: December 10, 2018, 03:22:14 pm
content: Quote from: amyk on December 10, 2018, 01:02:35 pmCan kinda understand the thought process though. Certainly not as bad as my HP laptop that was designed around a battery model that was not capable of delivering the power the machine required. Run both CPU/GPU at full load (like for video encoding) without the charger connected... the whole thing shuts down becasue it trips the overcurrent protection in the battery

author: coppercone2
author_rank: Super Contributor
timestamp: December 10, 2018, 04:09:08 pm
content: Component level repairing is kind of fallacy because how do you decide with confidence what chips are effected by something like a shorted power rail?For all you know a whole bunch of different silicone took minor damage, just because a part decided to jump on a grenade it does not mean no one suffered any injuries.I can see it being done with some things like maybe a front end thats fried from a sensor, but you still have to wonder, are the filter caps degraded? Did some dangerous HF go through the circuit and chowder anything else ?Then how do you price and guarantee something like that? Say a customer is buying from you because your the most reliable. Does a big business want to gamble with hardware from you that can go down? I have seen a repair job, replaced IC but someone missed the fact that the filter inductors were literary boiled. Dangerous for a company to do that for something that costs them 15$ with a guy thats paid at least 15$ an hour. The last thing you want to do is hassle someone even more by sending them something that has a hidden fault in it.Usuallyis not good enough. What happens to your reputation when you keep sending something back out from fixing? Do most people realize what the nature is of a complex electronic fix vs beating a body panel in a car?IMO usually you want to keep some of that stuff for internal tests and use around people that can fix it quick. Otherwise recycle.If someone else fixes it, then it breaks, its still better then the maker fixing it and having it break afterwards.

author: tooki
author_rank: Super Contributor
timestamp: December 10, 2018, 05:34:13 pm
content: Quote from: blueskull on December 10, 2018, 03:57:13 pmI know there are. But my sentence was "…places doing component-level repairson these things", and this thread revolves around MacBooks, which aren't that widespread in China yet, as I understand it. So even if they are technically offering that service, it's highly doubtful they're doing it on Rossmann's scale.Quote from: blueskull on December 10, 2018, 03:57:13 pmWhere did I compare with "cheap disposable computers"?I'm not aware of any rankings that compare reliability of individual product lines. So I used the rankings which are available, and they compare brands. And it's a fair comparison IMHO, because that covers what people actually buy, not what theycouldbuy but don't. (I wish people would buy more high-end computers like ThinkPads, but most people want cheap.)Quote from: blueskull on December 10, 2018, 03:57:13 pmI haven't used Thunderbolt so I can't comment.Quote from: blueskull on December 10, 2018, 03:57:13 pmYeah, the surfaces do scuff easily, not that that affects functionality at all.Quote from: blueskull on December 10, 2018, 03:57:13 pmIt appears some devices fail to negotiate the Power Delivery contract. I wonder if this can be fixed with a another software update? (There's already been one update to those adapters, no idea what it fixed.)Quote from: blueskull on December 10, 2018, 03:57:13 pmHence why Apple offers replacement service at the same cost as they used to charge for a user-replaceable battery alone. (I think it's gone up on some newer models, but by less than inflation. Apple charged $129 for a laptop battery for around 20 years, if my memory serves me.) Not sure what this issue has to do with the comment above, though.Quote from: blueskull on December 10, 2018, 03:57:13 pmUmm, I didn't realize that I had to restrict my comments on Apple functionality to EE, and specifically,yourapplications in EE.macOS works very well foreverythingI do. I'm not a content creator, they're just my personal computers for personal use. (Though I used a Mac at my old job, too, and I wasn't a classic content creator, either…) As for electronics, I'm a hobbyist and I can do everything I need in native Mac software. The fact that macOS may not be idealfor youdoesn't mean it can't be idealfor meand millions of other people, most of whom are not professional "content creators".Quote from: blueskull on December 10, 2018, 03:57:13 pmHow long does updating take in Win10? I haven't touched Windows since Win7 (haven't had any need to, since I left a job where I used it at work), and I remember how updates took a while, and in particular how you'd have to do repeated cycles of installing an update and then checking for more, installing those, checking again, often for many, many cycles. (Though it was nowhere near as bad as WinXP, where it could takedaysto get all the updates installed!)Not that install time is especially relevant to the day-to-day usability of the system and its ecosystem.(With that said, IMHO one of the biggest advantages of the Mac is Time Machine, the built-in backup system. With a backup on an external disk or network drive, if your Mac fails and you must replace it, restoring from a backup usually takes just a few hours, and when it's done, EVERYTHING is exactly how it was. At most, software with picky activation systems (like Adobe) might need to be reactivated real quick. Compared to reinstalling and configuring dozens of applications, this can save tons of time. To business users, this is a huge advantage. I've seen people saved by this when their system died and they had a looming deadline. Over the years — including very recently — I have seen Windows users express puzzlement at the fact that Microsoftstillhasn't outfitted Windows with a backup system anywhere near as seamless as Time Machine.)Quote from: blueskull on December 10, 2018, 03:57:13 pmYes. Look up the man page for the included "caffeinate" utility, or use a third-party tool like Insomniac, Amphetamine, or Caffeinated if you want a GUI.Quote from: blueskull on December 10, 2018, 03:57:13 pmFor sure, they're more configurable. Doesn't mean everyone needs or wants that configurability. A lot of us, even techies, value systems whose defaultsjust work.Quote from: blueskull on December 10, 2018, 03:57:13 pmNor does macOS. Apple haters think it does, because often the more complex commands are either just part of a drag-and-drop operation, or are altogether unneeded because the system handles it on its own. (Perfect example of that, at least a few years ago, was Windows users looking for a defragmenting utility, which the Mac doesn't have because it does that automatically on hard disks whenever a fragmented file is used.)You often just see Windows users looking for explicit commands on the Mac for things that we do in other ways. It's a perfectly valid difference.And remember, most users are not tech nerds like us, they neither want the complexity of Windows, nor does that complexity help them.Quote from: blueskull on December 10, 2018, 03:57:13 pmSo you don't want to mess with plists, but you want to mess with regedit, even though they function almost identically?!? (Key-value pairs, in nested hierarchies…)The Maccan'thave a registry editor, though, because there is no registry at all!! (The Registry was, after all, one of Microsoft's decisions that seemed smart at the time but REALLY came back to bite them in the end. So now MS has had to implement complex Registry virtualization to circumvent many of the issues.) Nearly everything that Windows puts in the Registry, the Mac compiles dynamically. (They are cached for performance into things that probably do resemble a registry, but those caches can be deleted with no deleterious effects.) The things that aren't compiled dynamically are held in plists, but they're never needed for the system to boot. You can normally delete a plist and it'll just be regenerated with the defaults.As for group policy, see e.g.https://www.infoworld.com/article/3055211/macs/manage-those-macs-a-guide-for-windows-admins.html

author: amyk
author_rank: Super Contributor
timestamp: December 11, 2018, 04:28:55 am
content: Quote from: tooki on December 10, 2018, 02:39:09 pmThe first PC with an RTC, the AT, used a MC146818 with a 100-year range (and the BIOS supplemented it with a "century byte".) MS-DOS date format goes to year 2107. These were both developed in the same decade as the Lisa.

author: tooki
author_rank: Super Contributor
timestamp: December 11, 2018, 02:23:09 pm
content: Quote from: blueskull on December 11, 2018, 02:14:57 am3. Power beyond 100mA still has to be negotiated, and I’ve found specific reference to the problem being PD contract failure, e.g.https://community.cypress.com/docs/DOC-134974. The cost of a finished battery is NEVER the cost of the bare cells, dude! Jeez Louise...This is an EE forum, everyone here should understand that the price of a product is NOT the same as the cost of the components!!5. Yes, we all knew that already. And? You missed my pointentirely.6. So it sounds like MS has finally gotten that under control.7. File History isn’t what Time Machine is for, bro. (Well, a file history is asecondaryfeature of it, but the main one is disaster recovery.) You can’t use Windows File History to restore an entire system, with apps, configs, data and all intact, can you?9. Well that’s the thing, IMHO Windowsdoesn’talways use sensible defaults. (And I don’t mean just preferences/settings, but also behaviors, etc. Often, changing behaviors requires third-party utilities which in turn make Windows less stable.) I do know MS has fixed some of my complaints in newer Windows, so I’m sure Win10 has further improvements I’d appreciate.(Remember, I’m not a Windowshater. I’ve had some very bad experiences with it, but it’s still a decent system overall. But it doesn’t stack up to Mac in the things I care about, so it’s not the right choice for me.)10. I think you’ve radically misunderstood what the dev docs are telling you, and I don’t think you understandwhyyou’re advised to use APIs instead of writing plists yourself. Regardless, this has nothing to do with being able to customize your own system, since the developer docs are for when you’re writing your own software. And even so, how is this any different from the Registry that you love so much? You can’t go in and edit it manually, either (it’s a RAM-resident database anyway; the on-disk file is just for persistence across reboots) — you have to use Windows APIs to manipulate Registry keys. (Regedit is just a front-end to this.) As a user of a Mac, you can go in and edit a plist file just fine using Xcode or another plist editor, or use thedefaultsCLI utility to manipulate individual keys.As for C vs Obj-C or C# or whatever... knowing C is great. But don’t crap on high-level languages and frameworks, you’re depriving yourself of a lot. Mac devs’ general willingness to use Apple’s APIs/frameworks (which at this point are only available in high-level languages) is why Mac applications end up behaving properly, since you get so many things for free. (For example, basic Undo functionality, drag-and-drop, assistive technology support, etc.) When you roll your own for things there are frameworks for, you usually end up with lower performance (since the framework/API has been optimized over time), reduced stability (again, the framework/API has been debugged over time), and user interface inconsistency (since very few low-level developers truly understand the minutiae of the UI widget behaviors of their platforms).But ultimately, you’re making the same mistake as so many Apple haters: you’re basing tons of your criticism on assumptions, namely the assumption that things are impossible or unsupported, just becauseyoudon’t know how to do it. But your not knowing doesn’t actually mean it’s impossible...Quote from: amyk on December 11, 2018, 04:28:55 amThe PC-AT is from mid-1984. The Macintosh, released in January 1984, had a clock that handles up to 2040. But again, my main point is that this criticism of the Lisa is absolutely absurd. As you just inadvertently explained, PCs that were the Lisa’s contemporariesdidn’t even have an RTC. And you ignored my main point: the fact that, collectors aside, people don’t generally use 16-year-old computers. You are holding Apple to an entirely different standard than the rest of the industry, in an effort to smear a company you don’t like. But it’s just making you look stupid.