RE: The power plug during upgrades

Hi Joe,

In Addition what was already, it depends mostly on the machine.

For example, all the low end models like the 520, 515, 800, 270, etc.
pp. do not have hot plug memory, or hot plug CPUs. I would assume the
bigger models to have that, but I don't know.

All 5xx models do have hot plug disks, hot plug PCI though, so you can
replace cards and disks while the system is up.

Replacing memory in any of these machines will require a power down.
IBM's instructions for the 520, 515 also say that you should unplug ALL
cables. If you have rackmount machine, it will still be grounded
(through the rack). If you don't, I'd suggest you to use a wrist strap,
or hope.

I usually wear a wrist strap when working on customer systems, but not
when working on some internal testing systems.

The planar board will still have power if the system is powered off - if
you have a screw or something that can conduct fall into the system,
you'll have one hell of a party (of course depending where it falls).

-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Joe Pluta
Sent: Saturday, October 20, 2007 4:31 PM
To: 'Midrange Systems Technical Discussion'
Subject: The power plug during upgrades

All my life, whenever I'm doing any hardware upgrades I have always
pulled
the plug from the socket. Now granted, this is for PCs; I don't have
much
of a track record on iSeries hardware.

I'm going to install some additional memory, and my natural inclination
would be to disconnect the power. However, I've had folks from IBM tell
me
to never remove the power except for the most dire situations, such as
replacing planar boards.

Those of you who have done this, what do you do? Do you disconnect
power?

Joe