[Asterisk-Users] Qs about FXO/FXS cards

[Steven Critchfield]

On Sat, 2005-01-01 at 17:25 -0700, Michael Welter wrote:
> Steven Critchfield wrote:
> > 
> > 
> > Those first 3 all sound like you have a problem with power supply and
> > consistency. You don't mention what modules you have in the cards, but I
> > bet you have FXS ports and have too light of a power supply for the
> > job.  
> > 
> 
> I'm not at the client sites, but my test system BIOS reports (with a 
> TDM22B installed):
> 
> VCORE	1.676V
> DDR Vtt	1.344
> +3.3V	3.28V
> +5V	4.945
> +12V	12.544
> 5VSB	4.945

And from BIOS you for sure are not loading a driver and you aren't
having to drive the ringing voltage. 

Part of my concern on power supplies is that I have abused them for non
standard functions and know that many of them will pulse the 12v lines
and probably the 5v lines as well if you draw too much power. So
consider the option that your server is running smooth with no activity
and the hard drive(s) spool down. Then a call comes in and asterisk goes
to trying to write to the disk for logging as well as generate ring
voltage. This could cause a low quality PSU to see a spike that it isn't
capable of handling and it would pulse and there is your power alarm. 
-- 
Steven Critchfield <critch at basesys.com>