[rescue] ultra 1 power supply question

Carl R. Friend crfriend at rcn.com
Sun May 17 12:43:06 CDT 2015

    On Sun, 17 May 2015, George Wyche wrote:

> Nothing happens when I press the switch to "1".

    I had a similar experience with a Netra NFS (which is an Ultra 1
under the covers, aka "Enterprise 150") when the internal UPS went
south.  Are you plugged directly into the wall or into a UPS?  If
the latter, try the wall.

> Do any of you know if that is sufficient to condemn the power supply? For
> instance I would get a bit further even if any of the power supply outputs
> were being shorted?

    If an output was shorted (unlikely) you'd probably see some motion
on the fans, even just a twitch.  If the thing is stone dead, I'd
suspect the PSU -- and if those are available for $25 it'd be useful
to have a spare.

    As a check, try unplugging the PSU from the motherboard and turning
the power on.  The PSU won't run unloaded, but watch the behaviour of
the fans; those will "twitch" if the PSU is OK.  If it's flat-line
then it almost certainly the PSU.

    On your locked license -- make real sure that you have the host
ID and MAC address written down someplace for when the NVRAM battery
goes flat!  Note: That is a *when* not an *if*, and the deadline


| Carl Richard Friend (UNIX Sysadmin)            | West Boylston       |
| Minicomputer Collector / Enthusiast            | Massachusetts, USA  |
| mailto:crfriend at rcn.com                        +---------------------+
| http://users.rcn.com/crfriend/museum           | ICBM: 42:22N 71:47W |

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