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

[David Abrahams]

on Mon Jun 16 2008, Henrique de Moraes Holschuh <hmh-AT-hmh.eng.br> wrote:

> 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.  

  Handle 0x0002, DMI type 2, 8 bytes
  Base Board Information
          Manufacturer: LENOVO
          Product Name: 2007B27
          Version: Not Available
          Serial Number: <censored>

That's all I get.

-- 
Dave Abrahams
BoostPro Computing
http://www.boostpro.com