[mythtv-users] 2 of 3 HD-5500 cards seen on power up, all 3 on reboot?

Brian Wood beww at beww.org
Sat Oct 9 00:18:13 UTC 2010


On Friday, October 08, 2010 06:05:17 pm Tom Dexter wrote:
> This one's been driving me insane forever.  My backend has three
> HD-5500 cards.  When I power up, without fail, it sees only two of the
> three cards.  However it always sees all three on reboot...drives me
> nuts.
> 
> Any idea what could be causing that?  I always figured it was some
> sort of anomaly regarding power or something.  I was hoping there
> might be some sort of udev configuration that might affect this.
> 
> At a bare minimum I'd like to at least know if there's a udev command
> I could use to find the card without rebooting.
> 

Is this something new? Did it work properly once?

If it worked once:

First thing I'd start looking into is a PSU problem. Those cards draw a fair amount of power (for a non-graphics PCI 
card). The PSU might be struggling to power them all, and might take a while to do so. The voltage might drop while the 
drives are spinning up, and be OK after they are all up to speed, and you might have a card that's not happy with the 
sagged-down voltage. On a reboot, the drives are already spinning, and would not pull the voltage down as much when 
rebooting.

If you have anything you call pull to reduce the total power draw, see if that makes a difference.

Might also be interesting to run lspci when in the "failed" condition, to see if all 3 cards are seen.


If it never worked correctly, there might be an issue with process timing at boot up.

This is just speculation, but experience tells me that most "odd" problems are often PSU-related.



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