[Amps] Capacitor plague

[N7HIY]

ah, the Hindenberg hydrogen incident of mother board electrolytics
and I thought they were bulging from being overfull of bytes
time to go out to the garage and burb my supply of ring mount CDE's
talk about global thermonuclear total destruction=

 snip
The first (and simpler) theory is that the failing capacitors can fail such 
as to form a short circuit, or with a very high leakage current, overloading 
the voltage regulators and causing them to overheat.

The second theory is that as the capacitance decreases and the ESR 
increases, the buck controller for the voltage regulator increases the 
switching frequency to compensate. Since most of the MOSFET's heat output is 
produced during the switching transitions, this causes them to overheat.

"The most common failure mode of the voltage regulator is for the MOSFET to 
short circuit, causing the system's power supply (5 or 12 volts depending on 
the motherboard) to be applied directly to the CPU, northbridge, RAM, or 
other components, causing widespread damage and destruction. As such, a 
motherboard with symptoms of failing capacitors should be taken out of 
service until it is repaired, to prevent further damage."

use cheap conterfeit knockoff parts then a cheaply designed and built 
circuit with no crowbar overcurrent overvoltage protection, so much for 
computer grade

Cliff N7HIY


"They that can give up essential liberty to obtain a little temporary safety 
deserve neither liberty nor safety."
Benjamin Franklin, Historical Review of Pennsylvania


----- Original Message ----- 
From: "Will Matney" <craxd1 at verizon.net>
To: <amps at contesting.com>
Sent: Sunday, March 19, 2006 23:55 PM
Subject: [Amps] Capacitor plague


> All,
>
> A very good article which I'm surprised made it to wikipedia.
>
> http://en.wikipedia.org/wiki/Capacitor_Plague
>
> Best,
>
> Will
>
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