[F10-nsp] Power Down and Up after restart

[Kabayan]

Hi all,
I got the problem about power DC Force10 (FTOS 8.3.1.1):

--  Power Supplies  --
Unit   Bay   Status       Type
---------------------------------------------------------------------------
  0     0     absent          
  0     1     up            DC 
 
-- Unit Environment Status  --
Unit  Status        Temp   Voltage             
---------------------------------------------------------------------------
* 0   online        50C    ok

 * Management Unit

In the log I only found:

Oct 14 23:23:38.79 UTC: %STKUNIT0-M:CP %IFMGR-5-OSTATE_UP: Changed interface state to up: Gi 0/42
Nov 24 14:32:15.265 UTC: %S50N:0 %CHMGR-0-PS_DOWN: Power supply 0 in unit 0 is down
Nov 26 11:58:40.701 UTC: %STKUNIT0-M:CP %IFMGR-5-OSTATE_DN: Changed interface state to down: Gi 0/32

The power just down, but no reason for this. The problem solved after I restart the switch (re-booting).We want to know the root case!
If someone has this problem before, please share to me here.

Kabayan