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The capacitor that Apple soldered incorrectly at the factory

downtowndougbrown.com

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Re: The capacitor that Apple soldered incorrectly at the factory

#251

Post by kalleboo »

sgerenser wrote: post #225
Waterluvian wrote: post #84

I spent my mid childhood on an LCIII. One summer my friend brought his Performa over and we tried to play 1v1 Warcraft 2 over the serial port. LocalTalk or something alike? But it just never quite worked right. I remember how frustrated and confused my older brother was. The computers would sometimes see each other but would drop off so easily. Was this that?!

Iirc Warcraft 2 came out well after the LCIII was obsolete (in fact, I’d be surprised if it was ever released for 68k Macs). Official system requirements list PowerPC and MacOS 7.6 as minimum required[1]. Maybe thinking of a different game? [1] https://www.blizzplanet.com/blog/comments/warcraft_ii_tides_...

Those requirements have to be from the expansion or something, I played a lot of WarCraft II on my 25 MHz '040 Centris 660AV back in the day (we also had a family Performa 5200 so my house was the only place my friends could play multiplayer networked WC2)

You can just about make out "68040" in the requirements on the box art here https://images-worker.bonanzastatic.com/afu/images/7569/5203...

Edit: found a photo of the expansion system requirements, also lists 68040 as supported https://cdn.mobygames.com/covers/4056502-warcraft-ii-beyond-...

Re: The capacitor that Apple soldered incorrectly at the factory

#252

Post by pkolaczk »

raxxorraxor wrote: post #83
jajko wrote: post #41

Earlier quoted context omitted.

TBH for such a critical piece of our modern lives, I would be more than fine to pay extra to be 100% sure I am getting original parts, put in professionally and in secure manner re my personal data. I wish ie Samsung had such service where I live. We anyway talk about expensive premium phones to start with, so relatively expensive after-warranty service is not shocking. This may actually eventually sway me into apple…

I don't. Such mechanisms also disqualify 3rd party replacements. It is just a wasteful solution. Not that any smartphone would qualify as decent here. But as a customer it will overall be more expensive for you.

3rd party replacements should be allowed but the firmware should allow me to check if any third party replacements have been made. I’d like to know when buying second hand phone if it has genuine parts. Third part replacements are usually of much worse quality (I tried that many times e.g. with third party toners for HP and every single time they turned out to be a waste of money).

Re: The capacitor that Apple soldered incorrectly at the factory

#253

Post by lproven »

rasz wrote: post #248
lproven wrote: post #233

Earlier quoted context omitted.

The +2 was an Amstrad product, not designed or built by Sinclair, though.

Didnt at least some engineers transfer after acquisition?

Maybe. I don't think a lot did. Amstrad did not acquire the company: it bought some rights to use the Sinclair Research brand.

That's why the next computer Sir Clive launched was the Cambridge Computers Z88. But note, some of the later bicycles were Sinclair Research branded:

https://en.wikipedia.org/wiki/Sinclair_Zike

https://en.wikipedia.org/wiki/A-bike

Amstrad did not acquire or develop the Sinclair QL, for instance, but it did sell Sinclair-branded x86 PCs.

https://www.computinghistory.org.uk/det/3404/sinclair-pc200/

It sold on some stock of existing ZX Spectrum hardware, but mostly it sold models it developed:

* Spectrum +2 -- a Spectrum 128 with a mechanical keyboard and built-in cassette drive

* Spectrum +3 -- a redesigned Spectrum 128 with a DOS from Locomotive Software and a 3" (not 3.5") floppy drive. Dropped compatibility with 48 peripherals such as Interface 1 and Microdrives, and 128 peripherals such as the numeric keypad, serial ports, etc. Added the ability to page out the ROM and replace it with RAM, so it could run CP/M 3, also ported by Locomotive.

* Spectrum +2A, the black +2: a cut-down +3 with a cassette drive.

These were designed by Amstrad engineers and contractors, and manufactured by Amstrad. No Sinclair involvement I'm aware of at all.

Re: The capacitor that Apple soldered incorrectly at the factory

#254

Post by xp84 »

kube-system wrote: post #187
harimau777 wrote: post #181

Earlier quoted context omitted.

A good engineer provides value to society. If they fulfill requirements that are bad for others then they are not good engineers. I seems to me that there is also a social dynamic to things. If consumer grade products become a race to the bottom then it is going to become more difficult for regular people to purchase products which aren't low quality. There's also a degree to which society (e.g. in the form of govern…

The fact that poor people can now afford to own some household appliances isn't a huge value to society? It completely changed the way our societies operate. I think it is a good thing that people have the option to buy crappy washing machines, rather than being forced to use the washboard and bucket my grandmother used. Yeah, they sometimes do develop a bad belt, or the timer mechanism might fail. But it beats being…

(Butting into your 2-person conversation to point out:)

> At the opposite end of the product value equation, every unused and functional component in every product that is no longer in service, is wealth that is wasted

This also is a counterpoint to your position though: of everything that goes into say, a fridge, it’s all wasted in 5 years now because Samsung chooses to put a PCB that is barely fit for purpose and will just fail with an error code, and because instead of putting such a failure-prone part behind a door and using an edge connector so it can be swapped in 5 minutes, they bury it God-knows-where in the chassis requiring an $800 labor charge, and charge $300 for the part. (As though that PCB is actually more complex than an iPad logic board, lol). So the whole 600 pounds of steel, refrigerant, insulation, glass, ice maker, and the compressor goes to the dump since who would invest $800 in a fridge that could have the same failure in a month and only the part is warrantied (you have to pay labor again). The poor people you’re worried about are buying these components over and over again because the appliance makers like this system. All this is done in bad faith. They’re morally bankrupt compared to their grandfathers who made appliances that lasted decades.

Re: The capacitor that Apple soldered incorrectly at the factory

#255

Post by johnklos »

upofadown wrote: post #219
johnklos wrote: post #82

It's a good thing that these machines don't even need -5 volts. With just the positive voltages provided, RS-422 still works, including LocalTalk. I think the -5 volts is only there in case an expansion card needs it.

I did a bit of research on this because I was confused about why RS-422 needed -5V. Normally the driver is powered off +5 and 0 Volts for RS-422. By increasing the swing down to -5, the Mac port is compatible with RS-232. So a Mac of this era can connect to a modem with a specially wired cable. No level conversion is required and RS-422 receivers are required to work down to -6V so the Mac is producing completely val…

I've wondered how my machines have worked without negative voltages, and this helps. Thanks!

These days, a charge pump device costs just a few dollars from Ali-express, so even though things work fine this way for many things, it wouldn't hurt to make them work for most if not all things.

When a replacement power supply does provide negative voltage, I try to use it, even if it does mean adapting -12 volts, which is what most ATX power supplies provide, to -5 volts, which is what, it seems, many 68030 Macs want.

Funny - I just did an ATX power supply for a Quadra 630, and it seems that most of the 68040 machines were using -12 volts instead of -5 volts (except the Quadra 605, which happened to use the same form factor and power supply as the LC / LC II / LC III).

Re: The capacitor that Apple soldered incorrectly at the factory

#256

Post by chefandy »

65a wrote: post #203
chefandy wrote: post #130

What’s the liquid in the old capacitors? PCBs? (as in polychlorinated biphenyls… that abbreviation collision always annoyed me.) I think I know exactly enough about electronics to ask more annoying questions than someone who doesn’t know anything at all.

Electrolytics are usually nothing too fancy, but it is proprietary. Water and electrolytes, hence the name. PCBs are in the big transformers and what used to be called bathtub caps which looked like this https://i.ebayimg.com/images/g/VjwAAOSwfGJjYtHx/s-l400.jpg (think 1950s electronics stuff)

Thanks!

Re: The capacitor that Apple soldered incorrectly at the factory

#257

Post by jopsen »

pokeymcsnatch wrote: post #161
jopsen wrote: post #158

Earlier quoted context omitted.

I've understood that capacitors can be used for timing, or smoothing a voltage after a power regulator (I think). How/what does adding capacitance help with?

Voltage spikes from line inductance, voltage drop-outs from line resistance. Basically you have little reservoirs of charge scattered all around the board (current flow isn't instantaneous in a real circuit). It helps to always think of current draw in a compete loop, out the "top" of the capacitor, through your IC, and back into the ground side (this isn't necessarily what's happening physically). Shorter loop means…

Thanks, that makes no sense to me :)

But I do recall having had inductance issues with high frequency transfers to an atmega.

I have no idea how a capacitor would help. Sounds like it would increase a signal delay (tiny one perhaps).

But definitely interesting, I'll need to learn about this if/when I dive further into electronics.

Re: The capacitor that Apple soldered incorrectly at the factory

#258

Post by rcxdude »

dotancohen wrote: post #222
RulerOf wrote: post #201

Earlier quoted context omitted.

It's true that the Phoebus cartel arranged to have light bulbs die after a certain number of hours, but bulb lifetime is a trade off between lumens, filament life, and energy consumption. The cartel-defined lifetime limit sits very close to the sweet spot for all of those metrics for incandescent bulbs. Technology Connections explained this well in a video about a year ago: https://youtu.be/zb7Bs98KmnY

> bulb lifetime is a trade off between lumens, filament life, and energy consumption At a specific temperature, using specific materials. There is no reason to suspect that material science would not advance. Or other constraints would change. A specific company choosing that particular sweetspot for a particular product line is fine. But a collusion between companies dictating that specific constraint (in lieu of, e…

>At a specific temperature, using specific materials.

The temperature of incandescent bulbs is directly related to the light that they give off, and tungsten is the obvious best material, there's no other materials on the horizon giving an improvement for the tech. It really is a pretty well understood tradeoff surface on a very mature technology (which was then displaced by completely different ones).

Re: The capacitor that Apple soldered incorrectly at the factory

#259

Post by rcxdude »

rasz wrote: post #250
weinzierl wrote: post #210

"The capacitor might not have been doing its job properly if it was installed backwards, but it didn’t seem to really be hurting anything." This is the buried lede! I am of the opinion that half of the capacitors in any modern circuit are useless; the trouble is we don't know which half.

This guy knew https://en.wikipedia.org/wiki/Madman_Muntz > He often carried a pair of wire clippers, and when he thought that one of his employees was "overengineering" a circuit, he would begin snipping components out until the picture or sound stopped working. At that point, he would tell the engineer "Well, I guess you have to put that last part back in" and walk away.[14] Techmoan recently did a video "The story…

You can still do it, you just need to do it in the EMC test chamber :P

Re: The capacitor that Apple soldered incorrectly at the factory

#260

Post by kube-system »

Dylan16807 wrote: post #241
kube-system wrote: post #236

Earlier quoted context omitted.

> That costs a ton. I just want a better lifespan, I don't want to 20x the duty cycle and also pay B2B prices. Therein lies the problem. A more durable product exists, and yet, even you don't want to pay more for it. And you are likely much more privileged than the rest of the world. What do you expect the rest of the world to be doing? Most of the world isn't picky about whether their hand mixer has plastic bushings…

> A more durable product exists, and yet, even you don't want to pay more for it. This is disingenuous as hell. I want to buy a version that cost 15% more to make. I don't want to buy a version that cost 3x as much to make (or is priced as if it does). When I can't find the former, that is part of problem. When I don't buy the latter, that is not part of the problem. > They're making these options intentionally becau…

> I want to buy a version that cost 15% more to make. I don't want to buy a version that cost 3x as much to make (or is priced as if it does).

Well, it just doesn't work that way. Premium components that truly extend product life are multiplicatively more expensive than what you'll find in value engineered products, if not exponentially so. Furthermore, a product that is 15% more expensive than competitors won't sell 15% fewer units, it will sell significantly fewer units, and then your fixed costs will also be higher, on top of the higher BOM costs.

Quality products with measurably longer lifespans in pretty much any product category are significantly more expensive than lower quality equivalents. The entire global manufacturing industry isn't in on some conspiracy.

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