Hi all I d be very suprised if the problems were related to elctrolytics caps on the motherboard, there's no new technology with making them these days and they are pretty reliable, in that type of use... BUT
the most unreliable place to put them is in switch mode power supplies, this is where they will dry out agive problems, crashes in the night can be caused by line transients, esecially in urban areas. often caused by the supply company switching sources, electrolyte caps wont do anything about line surges, unless they are for periods of greater than 100 mSec. I would be more inclined to put line transient protection on the supply to the pc, and maybe if your really worried, change the switchmode PSU in the pc, there only about $20. Definalty do not try to change ant thru hole component on a motherboard unless you know how to work with multilayer pcb's, and have some understanding of ESD HTH but probally caused more confusion. David wrote: > > Todd Lyons wrote: > > >Steven Lawrance wrote on Thu, Nov 08, 2001 at 07:50:43PM -0800 : > > > >>Since I'm just a software person and not an electrical engineer, a bad > >>capacitor means that I'll have to probably replace the motherboard, > >> > > > >Having been an electronics tech in a previous life, I can verify that > >electrolytic caps are a problem that gradually onsets. We used to get > >boards in that before we would even start checking parts, we would > >change all the electrolytic caps. The standing rule was if it's not > >been changed in less than 6 years, change it without question. Flaky > >caps on power supplies were the #2 most prevalent fix. (#1 was bad > >gate driver or base driver circuits, depending on if it was DC or AC > >equipment). > > > >Caps most frequently "dry out" in warm ambient temperatures. And it > >really is drying out. If you open a new cap and compare to an old cap, > >you'll see that it's much less moist. That also contributes to it > >getting warmer (and is mainly why they burn up...no moisture). I'd > >consider inside of a computer running for several years to be warm > >ambient temperature. > > > >Your mobo could very well be doing this if it's been in service for > >4 or more years. > > > >Blue skies... Todd > > > Generally you will see a residue (brownish) around an electrolytic cap > if it has gone > bad. That is the electolyte (dieletric) between the foil leaking out. > Replacing all of > them if less than 6 years is rather hard core and is the shotgun > approach. The only > reason to do that is if you #1) Don't know what the real problem is and > don't have the > tools to troubleshoot it. or #2) Work at a business where it is more > cost effective to > replace them all rather than pay labor cost to troubleshoot the problem. > Also lot of times the layperson will have more trouble finding the exact > cap to replace > than just replacing the board. > I'd look for leaky caps and if you don't see any residue, consider > moving your troubleshooting > else where. -- Richard Bown Ericsson Microwave Systems AB SE-431 84 M�lndal e-mail [EMAIL PROTECTED] tel +46 31 74 72422 mobile +46 7098 72422
