[rescue] rescue Digest, Vol 81, Issue 17

saquinn624 at aol.com saquinn624 at aol.com
Sun Aug 30 14:24:01 CDT 2009

Message: 1
Date: Thu, 27 Aug 2009 11:25:34 -0400
From: Ray Arachelian <ray at arachelian.com>
To: The Rescue List <rescue at sunhelp.org>
Subject: [rescue] v250 power supplies?
Message-ID: <4A96A56E.5030204 at arachelian.com>
Content-Type: text/plain; charset=ISO-8859-1


I just got a V250 that was destined for scrapping, but I can't power it
on.  When I plug in power (110V) to both PS's, they briefly blink the
green LED, then both switch the maintenance amber LED.  The front
maintenance amber LED turns on as well.

The PS's are getting power as I can feel their fans running.  If I hold
the front power switch for a few seconds, I see the case fans and the
CPU fans spin for about 1-2 seconds and then they stop.  I also see the
DVD drive briefly get power, but that's it.

I've tried unplugging power from the DVD, swapping the power supplies
around, powering just from one or the other, etc.  no luck. :-)

I am however able to login and talk to the LOM, which says both power
supplies need maintenance.  The LOM has "On" for undervoltage under
showenvironments(I think).
Is the undervoltage flag for the output of the power supplies or the
input (120VAC vs 240VAC?)  I've seen similar behavior for v490's if
hooked up to 110V instead of 240V - the LOM works but the system won't
power.   From docs.sun.com, and the label on the power supplies, this
box can work with 110-240V, but the behavior is a bit strange.

So I'm wondering is there a common failure with these power supplies?  I
find it odd that both have failed, but yet, either one alone can provide
power to the LOM.

Should I just buy a replacement power supply (some of which I see are
quite expensive). 

Could it be something else that's wrong?

I certainly wouldn't mind taking a power supply apart and replacing
parts, but which parts should I look at?
(Alternatively, is there any other way to power this specific
motherboard via any alternate power supplies from other machines?  Since
this is for home use, I don't really need dual power supplies or to fill
all 8 disk slots.  Anyone have pinouts for the power plugs on the



I haven't worked with Suns this new, but is sounds like it could be an environmental monitoring thing - I have a SGI Origin200 that displays similar symptoms, and it's because one or more (haven't troubleshot to that depth) of the PSU rails aren't on target, so the PSU comes on and then the system controller shuts everything down when it detects the problem. I've heard of other machines (most commonly Fuel) where one of the monitoring chips (Dallas something-or-other) is bad and the machine gets shut down for a thermal or voltage fault unnecessarily.

The fact that the PSUs stay on when not connected to the mainboard would support this.


More information about the rescue mailing list