31–40 of 50 posts
Earlier quoted context omitted.
what would you use? tantalums? ive have the joy of recovering old equipment with dried tant caps on the power rails. (23 of 'em!) maybe tants are made better these days...
argh. how does one delete comments? i refreshed by accident :(
Interesting post, I never knew about the Capacitor Plague! Will be sure to remember it.
Marginal (although not always illicit; sometimes just marginally spec-ed) capacitors have long been an issue including in consumer electronics. As an example, the Mac Plus power supply was notorious [well, at least if you were repairing them] for failing. Some people put out instructions for upgrading it by replacing a subset of components including IIRC certain capacitors. I've also read accounts of people improving…
The problems start to show up with stereo, though, where you have two channels to deal with. When you use low-quality components, the phase shift can be significantly different between the two channels. (Components have a, say 10% value tolerance. If one channel is +10% and the other is -10%, you have a problem.)
This difference destroys the phase information between the two stereo channels, resulting in poor "imaging".
When you replace the 10% tolerance components with 1% tolerance components, you lose the phase distortion, presumably increasing sound quality.
(I am not an EE, but I have built a lot of headphone amps. The sad part is how people with $1000 amplifiers often have worse components than an amp built from $30 worth of parts. Ah, the free market...)
I once bought a set of monolight strobes (for photography) made by a respected brand name (Bowens.) Every unit in the set failed shortly after the 1-year warranty due to failure of the electrolytic capacitors in the power supply. I used these lights heavily, so for other users, they might last two or three years. That's still a remarkably short time to failure for this kind of component.
A friend has an Apple iMac G4 that they paid a shed-load of cash for and expected to last well - it nearly made 3 years. The point of failure? Electrolytic caps in the [overheating] graphics card. The card is soldered in on the screen side of the mobo.
Earlier quoted context omitted.
Marginal (although not always illicit; sometimes just marginally spec-ed) capacitors have long been an issue including in consumer electronics. As an example, the Mac Plus power supply was notorious [well, at least if you were repairing them] for failing. Some people put out instructions for upgrading it by replacing a subset of components including IIRC certain capacitors. I've also read accounts of people improving…
This is indeed true. Some (all?) amp designs place resistors and capacitors in the signal path. This distorts the sound. For one channel, that would be fine, since the distortion is usually just a phase shift that you won't notice. (Play a song. Then play a song but start it 1ms after you were planning to start it. It will sound fine both times :) The problems start to show up with stereo, though, where you have two…
For about 6-9 months in 2006 We had a series of Dell Optiplex GX 270s that had a remarkable failure rate - close to 60% of our systems failed. We knew that Dell must have been having a tough time, when the FIRST question they asked on a support call was whether we saw any "Bulging Capacitors on the Motherboard" - I mean, not "Have you Tried Rebooting", or, "Have you tried powering down for 90 seconds", but "Do you ha…
Also, we had a Dell 'certification' that essentially let us go to a part of the website, and order the replacement parts for any warrantied system. It was really slick. When the site didn't get it done, there was a super-secret US-based support line we could call :)
So, for hardware manufacturers, is there any reliable way to identify good quality caps?
I assumed that they were carefully designed so that the electrolyte would go off just out of warranty (no I'm not kidding) and force a resale. Perhaps electronic manufacturers that are big enough could have a state mandated "cost of parts and actual labour costs" repair service.
actual labor costs quickly make repair more expensive than replacement.
Earlier quoted context omitted.
That is a different sort of ripple. Your big electrolytic capacitors are used in the AC/DC conversion where the rectified sine wave is smoothed into a constant voltage. | | | _ _ _ ===>> | | / \ / \ / \ / |-------------- +V---V---V---V- +--------------- The capacitors store energy during the peaks and return it during the troughs. The ripple is the current in and out of the capacitor which heats them and does "stuff-…
It looks like lifetime is specified in hours of life at a high temperature - e.g.: http://www.rubycon.co.jp/en/catalog/e_pdfs/aluminum/e_BXF.pd... Lifetime is specified at 10000hrs at 105deg C. As temperature decreases, lifetime appx doubles per 10deg C: http://www.low-esr.com/endurance.asp It looks like a cap rated at 4000h @ 105deg C should last around 60 years at 100deg F or so. Anecdotally I have a guitar amp mad…
Earlier quoted context omitted.
How did they fix a hardware failure in 4 hours? Telekinesis? Teleportation? Is there something I'm not understanding?
Enterprise customers can get hardware replacements same-day.
It was damn slick.