Quote:
Originally Posted by
pondosinatra 
As someone who's had to shell out a bunch of money and be stressed to the max getting my old SE/30's, IIci's etc. recapped I find it quite annoying that Apple is still using the same capacitor technology in their current products.
Why are they not using Tantalum caps???? Anyone? Oh right, designed for future failure.
Bad components happen. Doesn't matter what's kind it is, if the part was bad, it's bad. If Apple (or Dell, IBM, HP, or anybody else for that matter) gets a bad run of components from a dishonest Taiwanese component manufacturer that don't meet the specs they were <supposed> to, you can hardly point at Apple (or the others) and say "designed for future failure" (and be taken seriously anyhow). At worst, you can say that got taken by a shady component manufacturer who didn't sell them the parts that they paid for - which is exactly what's happened with <all> of the mentioned companies, and many more, at one point or another over the years. The result is a bad run of finished product that experiences premature failures. I have a 2005 Quad G5 that's seen 10's of thousands of hours of power-on usage, and it's never had a failure. It's the same capacitor technology there too. The components were specced <and built> to meet the operating environment conditions (my poorly-ventilated, stuffy little home office ;)), and they didn't fail. Easy.
Quote:
Originally Posted by
pondosinatra Um. Wrong. Most SE/30's that aren't recapped are no longer working or are exhibiting symptoms of cap leakage which corrodes the motherboard.
In fact I would suspect that most component failures in any electronic device are due to cap failures.
There's a very active community of people dedicated to replacing these ticking time bombs which tantalum caps which will never leak.
On the flip side, all my Amiga's which are even older than my SE/30's which use Electrolytic caps are perfectly fine - granted the form factor would be an issue these days.
I just question when I'm spending such a premium price for a Mac they couldn't have thrown in better caps.
I never had any of my II-series Macs die on me for any reason. I did have a motherboard fry in a Wallstreet powerbook once - but a transformer on pole just outside my house exploded during an electrical storm ... so I'm guessing that can't really be blamed on a capacitor failure. :P I find it interesting when people try to make authoritative statements like "all my XYZ's of type Q die/break/whatever so therefore this/that/th'other is wrong with them". It's interesting because in many of those cases, the most significant link in the series of failures is the <person> making the claim (or their usage/environment). Have you been living in the same house (or maybe even just same town) for 30 years? Maybe you have bad electrical service in the house and you get voltage fluctuations that go far outside of the norm, maybe that's why you see so many capacitor failures, you're feeding your devices bad power that's well outside what the parts were usually specced for. Maybe you should invest in mil-spec gear that is rated for more extreme operating conditions?
You're making some bold, sweeping statements here with those "most" comments. Care to support any of them?
"Ticking time bombs"? That's not too much of a hyperbole, right? My G5 didn't fail, your Amiga(s) "are perfectly fine", countless other devices utilizing liquid-electrolyte aluminum capacitors running for a couple <decades> haven't failed. A significant production run of SE/30's that ended up with faulty capacitors did - but again, those were <faulty>. If they'd been faulty CP tantalum capacitors, they'd have failed too. The argument presented is flawed - or at the very least, not supported by the evidence provided.
If you're using a capacitor with a solid electrolyte, you are correct, it will "never leak". But, why does a liquid-electrolyte capacitor leak? Answer: for the same reason that solid-electrolyte capacitor explodes and catches fire, operating it in conditions which exceed it's tolerances.
"Better" is a relative term. Better for what particular conditions? More reliable when running in higher temperature environments that an iMac will realistically never experience? Are you suggesting an extremely low ESR required for iMac longevity? If so, why not suggest they go ceramic and not mess with electrolytics (tantalum, aluminum, or otherwise) at all?
As for tantalum capacitors (which, by the way <are> electrolytic) ... just a guess, but: higher cost, not available with the specifications required, and/or if they fail, the very real potential for catastrophic thermal runaway leading to nasty fires (not something a consumer product manufacturer wants to deal with if they can avoid it ;)).
Lazy me quotes Wiki, who says:
"... unlike aluminum electrolytics, they are intolerant of positive or negative voltage spikes and are destroyed (often exploding violently) if connected in the circuit backwards or exposed to spikes above their voltage rating.
Tantalum capacitors are more expensive than aluminum-based (with liquid electrolyte) capacitors and generally only available in low-voltage versions, but because of their smaller size for a given capacitance and lower impedance at high frequencies they are popular in miniature applications such as cellular telephones."
Also,
"Multilayer ceramic capacitors are increasingly used to replace tantalum and low capacitance aluminium electrolytic capacitors in applications such as bypass or high frequency switched-mode power supplies as their cost, reliability and size becomes competitive. In many applications, their low ESR allows the use of a lower nominal capacitance value."
So, again, why not more ceramics?
Bottom-line, operating specs and reliability metrics apparently all meet or exceed Apple's criteria (whose completed products typically have a usable lifetime of two or more times than that of similar products from other companies), and cost less to boot, so why <not> use the ones they did?
