I have repaired lots of motherboards in my working time, mostly
replacing capacitors in the vicinity of the main processor. There they
are used to make the 3 volts for the CPU from 5 or 12 volts. The mobos
showed all kinds of funny behaviour. For instance, one of my own PCs
started counting up in Excel as soon as a number was entered in a field.
Obviously, the CPU somehow counted the ripple of the 3 volts buck converter.
Considering the high current draw of GHz processors, there are some 20
or more amperes flowing through the little leads at, say, 50 kHz. No
wonder the capacitors get warm, the electrolyte expands and eventually
blows the lids. Therefore, the caps are the first thing I look at when I
get a dead mobo. It took some time until industry reacted to that and
made temperature proof capacitors (105° ore more).
Formerly, we also repaired PC power supplies having the same problem,
but at today's prices that doesn't pay any more.
Peter
Am 01.02.2020 um 09:09 schrieb Gregg Eshelman via Emc-users:
Nearly all manufacturers of electronics from the 1990's into the early 21st
century ended up getting at least some of those faulty capacitors, such was the
massive quantity of counterfeits made with the bad electrolyte formula. Apple
seemed to have been especially hard hit.
On Friday, January 31, 2020, 8:54:51 PM MST, dave engvall
<dengv...@charter.net> wrote:
Certainly an idea to check out. Never occurred to me but the I suppose
Intel could be victim of that kinda of fraud as easily as other
vendors. It is on tomorrows list of things to do. Tnx
Dave
On 1/31/20 7:16 PM, Gregg Eshelman via Emc-users wrote:
Have you checked the board for leaking capacitors? Usually the pressure relief
cuts on top of the cans split open.
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