What I've seen happen is a PS that loses stability and keeps varying the output voltages according to variances on the input. Most computers are very sensitive to the DC voltage variations, so the PS has to be as stable as possible.
You can always put a scope on the DC output and analyze it, there should be virtually no ripple, and the generally accepted voltage variation should be max up to +/- 0.2V on any of the rails, mainly 12V and 5V, for a decent PS. I've seen brand new PS's give 0.5V variation out of the box, and often times it leads to all sorts of funky events. On Mon, Jul 20, 2009 at 7:50 AM, David Kaiser<[email protected]> wrote: > Hey Todd, > > I've never heard of power supplies degrading. That is pretty > interesting. I may have to try that if I can ever suspect that a power > supply is causing interference noise, etc. > > how would you measure if a power supply is doing this? Can you use a > scope and look at the supply voltage, etc. ? Or do you just replace it > and if it goes away, then you fixed it? > > DK > > On 7/20/2009, "Todd Lyons" <[email protected]> wrote: > >>On Sat, Jul 18, 2009 at 8:41 PM, Jeff Lasman<[email protected]> wrote: >>> >>>> If you cant do a memtest, then you could just change the ram to >>>> something better and/or not bad. In some cases, ie) kingston ram, >>>> you might need to up the voltage. Just a guess. >>>> >>>> What kind of ram are you running on this server? >>> >>> Unfortunately I don't know and as far as I know I'd have to shut down >>> the server to find out. >>> >>> Here's what I do know... we buy the servers populated with ram, by >>> ServersDirect, a rather well-known and respected provider. When we >>> need more memory, we buy it from them as well. >>> >>> This is the first time we've ever had a problem that could relate to >>> memory, in about eight years of using these servers. >> >>Just some off the way observations from someone who has a few old >>VALinux and HP boxes still in use (440BX mobo). >> >>Are these particular servers 5+ years old? One thing to consider is >>that the power supply could be degrading which causes more noise (not >>regulated as well) and putting a new one in could make the instability >>go away. >> >>Any buildup of dust? That's insulation, making it harder for heat to >>be dispersed. Or in general, poor airflow in that area. If it's in >>your colo though, I really doubt it, and I'd be very concerned if >>there was dust buildup in the computer(s). >>-- >>Regards... Todd >>_______________________________________________ >>LinuxUsers mailing list >>[email protected] >>http://socallinux.org/cgi-bin/mailman/listinfo/linuxusers > _______________________________________________ > LinuxUsers mailing list > [email protected] > http://socallinux.org/cgi-bin/mailman/listinfo/linuxusers >
