[ltp] Re: [NOT SOLVED] Immediate Poweroff when Docking

Henrique de Moraes Holschuh linux-thinkpad@linux-thinkpad.org
Mon, 16 Jun 2008 23:31:52 -0300

On Mon, 16 Jun 2008, David Abrahams wrote:
> on Mon Jun 09 2008, Henrique de Moraes Holschuh <hmh-AT-hmh.eng.br> wrote:
> > On Thu, 15 May 2008, Henrique de Moraes Holschuh wrote:
> >> On Wed, 14 May 2008, David Abrahams wrote:
> >> > Just happened to me again as well :(
> >> 
> >> What happens if you dock with the dock's power supply *disconnected* (I
> >> do mean unplugged, I don't mean just "off") and connect it only after
> >> docked?
> >
> > Did you try that?  I asked you to try it for a good reason, it has
> > a non-zero chance of fixing your issue.  You may want to try it with
> > and without the rubber caps.
> I've been swamped with work, and then travelling, so it hasn't exactly
> been practical to do this.  I don't know what happens if I dock with the
> power supply disconnected, but

You would have a very different grounding condition.  The rubber caps and
Lenovo comments make it very clear that the issue is either one of different
static charge potentials (power brick disconnected), or one caused by
different ground potentials (power brick connected).  The later is much
stronger, so trying it with the power supply disconnected would be a lot
more likely to reduce the inrush current enough that it wouldn't crash the
PCI bus or whatever IBM/Lenovo forgot to harden.

> a) The problem happened so rarely (especially since the installation of
>    the rubber caps) that it would take a great deal of experimentation
>    to learn the answer.

I see.

> b) In response to my problem report, IBM replaced my motherboard.  With
>    the rubber caps I haven't had a single incident so far since the mobo
>    replacement.  We'll just have to see if anything is actually wrong
>    anymore.

Well, certainly a new motherboard might be more resilient to whatever the
issue is...  I wonder if they didn't actually fix it up on the mobo as well,
and the caps aren't just an attempt to avoid recalling a lot of planar cards
and docks.  See if dmidecode doesn't give you a version number for the
motherboard.  If it does, we could compare with the ones on others having
the same issue.  If yours is a newer version, the others would have some
reason to pester IBM/Lenovo for a replacement.

> c) Needing disconnect the power-supply before docking is better than
>    losing everything, but for me that wouldn't amount to "fixing my
>    issue." ;-)

Heh :-)

> Unless the problem comes back I don't have much motivation to pursue
> workarounds.  I hope you can understand.


  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh