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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

#111

Post by amluto »

nuancebydefault wrote: post #91
yetihehe wrote: post #80

Earlier quoted context omitted.

That device was a cheap wifi power plug, had cheap unisolated power supply, it was never intended to have user accessible electrical parts sticking out, so no need for isolation. In such cases device has common ground with ac voltage. I don't know all specifics, but NEVER connect any single terminal of 220V plug to your computer ground (usb ground in this case). When it's properly grounded, most devices will survive…

If i remember correctly, a lot of power supplies of cheap electronics have AC-coupled the low voltage side with the mains side. There's no physical wire, just a capacitor. You can often feel the AC when touching the 'safe' side of the adaptor.

Forget “cheap”. As far as I can tell, many modern ungrounded power supplies, including Apple’s, have enough A/C coupling from the line to the output that you can feel a bit of tingling when you touch a metallic object connected to the output.

Re: The capacitor that Apple soldered incorrectly at the factory

#112

Post by xattt »

blitzar wrote: post #103
xattt wrote: post #68

Earlier quoted context omitted.

32K ought to be enough for anybody.

32K is going to look so lifeless and dull after you try 64k.

When will the pixels start to approach erythrocyte-level density like on the Vision Pro?

edit: Anywhere between 208K to 277K.

Re: The capacitor that Apple soldered incorrectly at the factory

#113

Post by klysm »

ethernot wrote: post #35

There are so many cases of this sort of stuff it's unreal. But it gets even stupider. I found one a few years back when I repaired a linear power supply. This required me to reverse engineer it first because there was no service manual. I buzzed the whole thing out and found out that one of the electrolytic capacitors had both legs connected to ground. They must have shipped thousands of power supplies with that erro…

That seems like one the least harmful mistakes you could make. Capacitors are sprinkled all over boards in excess’s because it’s probably better than not enough capacitance.

Re: The capacitor that Apple soldered incorrectly at the factory

#114

Post by klysm »

jcims wrote: post #96
ethernot wrote: post #35

There are so many cases of this sort of stuff it's unreal. But it gets even stupider. I found one a few years back when I repaired a linear power supply. This required me to reverse engineer it first because there was no service manual. I buzzed the whole thing out and found out that one of the electrolytic capacitors had both legs connected to ground. They must have shipped thousands of power supplies with that erro…

I have a 3D printer where presumably a smoothing cap just fell off the X axis controller section of the mainboard. Didn't make a lick of difference in anything operationally. Still works great.

Checks out, most boards are made with very conservative amounts of decoupling capacitance because it’s way easier than dealing with random failures due to not enough capacitance

Re: The capacitor that Apple soldered incorrectly at the factory

#115

Post by kstrauser »

krige wrote: post #47
codewiz wrote: post #6

Commodore had 3 capacitors mounted backwards on the A3640, the CPU board of the Amiga 4000 with 68040 processors: https://youtu.be/zhUpcBpJUzg?si=j6UFmIJzoC-UDS6u&t=945 Also mentioned here: https://amiga.resource.cx/exp/a3640

Commodore just kept doing this. Just listing shoddy craftsmanship would take forever, and then we get to intentional bad decisions, like giving the A1200 a power supply that's both defective (capacitors ofc) and barely enough to support the basic configuration with no expansions, which is extra funny because PSUs used with weaker models (A500) had greater output...

This was the hardware patch I had to install to use a CyberstormPPC: https://powerup.amigaworld.de/index.php?lang=en&page=29

Re: The capacitor that Apple soldered incorrectly at the factory

#116

Post by kstrauser »

shiroiushi wrote: post #25
tobr wrote: post #16

Earlier quoted context omitted.

This. I’ve known a TV that was in more or less daily use for over 30 years. Not sure why we stopped expecting that from electronics.

>Not sure why we stopped expecting that from electronics. For TVs specifically, the technology changed a lot. For a long time, everyone was stuck on the NTSC standard, which didn't change much. At first, everyone had B&W TVs, so once you had one, there was no reason to change. Then color TV came out, so suddenly people wanted those. After that, again no reason to change for a long time. Later, they got remote control…

Great points. The TV I have today is approaching my platonic ideal screen. It’s as big as it can get without having to continually look around to see the whole screen. Sit in the first row of a movie theater to understand how that can be a bad thing. The pixels are smaller than I can see, it has great dynamic range, and the colors can be as saturated as I’d ever want. There’s not much that can be improved on it as a traditional flatscreen video monitor.

Re: The capacitor that Apple soldered incorrectly at the factory

#117

Post by xxs »

nuancebydefault wrote: post #95
rvense wrote: post #39

Earlier quoted context omitted.

But when it does, it will probably be the capacitors in the power supply that have dried out.

How can I even know which capacitor is faulty?

That would require some experience, yet the most common visual clue would be 'bulging'. There are some ways to measure ESR w/o desoldering but they won't be reliable at all times.

Measuring voltages, peak to peak, is a bit more work.

Re: The capacitor that Apple soldered incorrectly at the factory

#118

Post by moooo99 »

ethernot wrote: post #43
fragmede wrote: post #27

Earlier quoted context omitted.

not capacitors, but more advanced components, like the camera, have serial numbers embedded in them, and the serial number needs to match, otherwise it won't accept the component. Components off a stolen device are put on a list and won't work in admirer another phone, so stolen phones aren't even worth anything for parts, driving down the market for stolen phones. It also makes the job of repair shops harder, which…

The only reason this is an issue for repair shops is they can't sell you recycled stolen parts at bottom of market prices for a sky high mark up. On top of that the "non genuine parts", some of which really are utterly dire, show up in the OS as being not genuine parts. Buying genuine parts, which are available from Apple, eats into the margins. There is very little honour in the repair market, despite the makeup app…

> The only reason this is an issue for repair shops is they can't sell you recycled stolen parts at bottom of market prices for a sky high mark up.

This is just incredibly dishonest framing and completely ignoring what the right to repair and third party repair shop issue is all about.

> Buying genuine parts, which are available from Apple,

It is not a margin problem, it is an availability problem. Apple does not allow third party repair shops to stock common parts, such as batteries or displays for popular iPhones. This is only possible when providing the devices serial numbers. This effectively prevents third party repair shops from competing with Apple or Apple authorized service providers because they have artificially inflated lead times.

Becoming Apple authorized isn't an option for actual repair shops because that would effectively disallow them from doing actual repairs when possible, rather than playing Dr. Part Swap. Everything what Apple does in the repair space essentially boils down to them doing everything they can to avoid having competition in the repair space.

> eats into the margins

Replacing a 45ct voltage regulator on a mainboard is cheaper than replacing the entire mainboard with everything soldered on is cheaper, but doesn't allow for very nice margins.

> There is very little honour in the repair market

There is very little honour in any market. Honour does not get rewarded nowadays, people are in to make money, if you're lucky they still take a little pride in their work. If a repair shop offers good service or not should be up to the consumer to determine, not up to Apple (or any electriconics manufacturer that employs the same tactics).

> makeup applied to it by a couple of prominent youtubers and organisations.

That is called marketing, that's what Apple does also pretty good. They're also lying when they say they are environmentally conscious while they also have their genius bar employees recommend an entirely new screen assembly on a MacBook just because a backlight cable came loose.

> The amount of horror stories I've seen over the years from independent repairers is just terrible. J

The amount of horror stories I have experienced with Apple is no joke either. Apple is always taking the sledgehammer approach with their repairs. I've had the pleasure myself to deal with Apple repairs once for my old 2019 MBP. It wouldn't take a charge anymore, went to the Genius Bar and received a quote for a new mainboard costing well over 1000 EUR. Being familiar with some of the more technical videos of Rossmann etc, I found one electronics repair store that actually does board level stuff and got it fixed for a fraction of the price (iirc it was ~200 EUR).

Re: The capacitor that Apple soldered incorrectly at the factory

#120

Post by spockz »

amluto wrote: post #111
nuancebydefault wrote: post #91

Earlier quoted context omitted.

If i remember correctly, a lot of power supplies of cheap electronics have AC-coupled the low voltage side with the mains side. There's no physical wire, just a capacitor. You can often feel the AC when touching the 'safe' side of the adaptor.

Forget “cheap”. As far as I can tell, many modern ungrounded power supplies, including Apple’s, have enough A/C coupling from the line to the output that you can feel a bit of tingling when you touch a metallic object connected to the output.

How is this even allowed? My tv had it. My MacBooks since time memorial have it. They all feel “spicy”.
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