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Re: System downtime wednesday for maintainance.

From: Bill Hacker <wbh@xxxxxxxxxxxxx>
Date: Fri, 18 Aug 2006 01:37:48 +0800

Peter Avalos wrote:

On Thu, Aug 17, 2006 at 04:41:00PM +0800, W B Hacker wrote:

Have you noticed any electrolytic capacitors - probably in VR section - with slightly bulged tops? Some of those have taken a *long* time to work thru the system and fail - long after the 'big wave' has largely passed from memory.

Or maybe it's a new round of bad electrolyte....


I had a similar problem a few weeks ago.  I referenced this site:


That site does note that the problem has not gone away.

But part of it may not be bad electrolyte. Simply that designers and component logisticians are not as conservative as to de-rating electrolytic caps subject to high ripple and high temperature as they once were. And/or that makers are too confident in their ratings..

*ALL* electrolytic caps have a finite life, though most will outlast the MB they are installed in for obsolesence reasons. IF it is run cool and under 'consumer' workload....

Unlike the plain-Jane borax and water B+ filter caps in my 1938 Sparks-Withington all-band receiver .. When upgrading from a 5Y3 to a 5U4 then to a 5R4 rectifier tube still left the plates glowing a dull red and added the smell of transformer windings melting their varnish, it was time to 'recap'...


When the original 180 MHz PentiumPro was still a 'hot' item, I had a pair of HK$ 10,000+ per-each dual PPro PCMCIA SBC's fry their entire VR sections...



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