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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

#161

Post by pokeymcsnatch »

jopsen wrote: post #158
klysm wrote: post #114

Earlier quoted context omitted.

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

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 less inductance, shorter traces less resistance.

Re: The capacitor that Apple soldered incorrectly at the factory

#163

Post by xxs »

toast0 wrote: post #126
xxs wrote: post #75

Earlier quoted context omitted.

Few usually means 3-5 or so, a half decent TV would be at least half a grand. That's rather high hourly pay rate.

Explain to me why this tv for $100 [1] isn't perfectly suitable to replace a 2008 40" 1080p Samsung LCD with florescent backlight that 2was a deal at $1000. Yeah, you could get something bigger and better. Yes, price comparison on a sale week is a bit unfair. [1] https://www.bestbuy.com/site/tcl-40-class-s3-s-class-1080p-f...

FYI: bestbuy is unavailable outside the US (the site I mean), or likely NA.

Re: The capacitor that Apple soldered incorrectly at the factory

#164

Post by jcims »

robomartin wrote: post #100
jcims wrote: post #96

Earlier quoted context omitted.

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.

It could be there to control emissions. You’d need to analyze the circuit to determine its purpose.

Very possible! I actually have a 100MHz scope and sdrs that tune from 9khz to 2ghz, could be an interesting distraction on the weekend to see if that axis is any noisier than the others.

Re: The capacitor that Apple soldered incorrectly at the factory

#165

Post by jajko »

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.

There are things in life where amount paid is far from top priority, and phone is one these days. With sums we talk about, I just don't care anymore, and Samsung I have now is even more expensive and more wasteful.

Re wastefulness - a decent laptop causes 10x more pollution to manufacture than phone. Desktop PC 10x that. TVs. Cars. Clothing. Phones are very much down a very long line of higher priority targets for eco friendly approach.

Re: The capacitor that Apple soldered incorrectly at the factory

#166

Post by bigstrat2003 »

shiroiushi wrote: post #5
toast0 wrote: post #4

Earlier quoted context omitted.

If they do a recall, it will say they should be discarded. Sony has a recall on all its trinitron tvs made before the end of 1990 like this: https://www.sony.jp/products/overseas/contents/support/infor...

This shouldn't be allowed at all: if the product was bad all along, they should be required to fix it, and shouldn't be able to say "well, it's old, so you should just trash it", which means they don't suffer any penalty whatsoever.

That is completely unreasonable. Companies can't be expected to take in and repair devices that old.

Re: The capacitor that Apple soldered incorrectly at the factory

#167

Post by bigstrat2003 »

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…

If you think Apple's part pairing policy has anything to do with consumer benefit, I have a bridge in Arizona to sell you.

Re: The capacitor that Apple soldered incorrectly at the factory

#168

Post by MBCook »

fredoralive wrote: post #40
PeterStuer wrote: post #21

In the mid 80's I was the head of the CS student chapter. We ran the computer rooms for the science faculty. We had a room with about 20 Mac 128k. I do not know where Apple sourced their capacitors from, but these were not A-tier. A Mac going up in a puff of white smoke was a weekly occurrence. We had a few in reserve just to cycle them in while they were out to Apple for repair. P.S. still my favorite Mac of all tim…

With things like the Mac 128k, reliability issues may partly be down to Steve Job’s dislike of cooling fans.

I was just thinking of the Apple III the other day.

If I remember, jobs had them not include a cooling fan. As it would heat up and cool down the chips in the motherboard would work their way out of the socket. So one of the official solutions to try if you were having issues would be to drop it a couple of inches to try and get the chips to re-seat inside.

Crazy.

Re: The capacitor that Apple soldered incorrectly at the factory

#169

Post by MBCook »

sroussey wrote: post #162

I have an original Mac that no longer turns on. I bet there is a capacitor to replace. This is giving me the energy to go look for it!

There’s a very good chance the battery has leaked and caused quite a mess. Well capacitors are a problem the battery is the biggest one.

Re: The capacitor that Apple soldered incorrectly at the factory

#170

Post by owenversteeg »

Workaccount2 wrote: post #129
magic_smoke_ee wrote: post #125

Earlier quoted context omitted.

Intentional planned consumption/obsolescence by design. This class of problem is where under-regulation and lack of standards benefits only sellers and cheats buyers. PS: Also, Amazon should be required to test all of the electronic, safety, and food products on its site such that they can prove safety and standards conformance.

I am assuming you are an ee (like myself)...I have never designed a product with a built in expiration, nor have I ever seen any app notes or write ups on the engineering of it - something engineers love to do. What I have seen done is cheaping out on parts in order to get the price as low as possible, because customers shop primarily on price. Not to lash out, but it kind of hits a nerve for me, because people think…

I agree with what you said - engineers do the best they can with the budget but the budget is small because people won’t pay for things that last - but it’s worth saying that any boards with electrolytic capacitors have an inherent built in expiration. Any product with rubber has an expiration. Any product with permanent batteries, glued or sealed assemblies, or no spare parts. Much of that is with the customer’s budget, sure. But these days, even among expensive things, nearly nothing is built to last.
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