On Tue, 24 Feb 2009 18:49:11 -0500, Lewis G Rosenthal wrote:
>I would suspect system firmware and/or embedded controller firmware. Do
>you get the same behavior docked and undocked? On battery vs AC adapter?
>(Yes, there is a difference between the docked power and the jack in the
>back of the machine).
1) Since there have been absolutely no changes made to this
system, why [other than a hardware problem] would this
condition just all of a sudden appear.
2) I've not really tried in the dock, but it is identical with
the jack-in-the-back power or operating on battery. And,
because the 'flashing' is unpredictable, other than leaving
it in the dock and monitoring it, finding it misbehaving is
a bit problematic.
>I'm thinking that this may be a low voltage condition of some sort. The
>hardware switch is not actually hardwired directly to the Wi-Fi card,
>but instead, should be connected to the system board. Thus, an errant
>circuit on the board (even something as mundane as a bridge rectifier,
>or a hairline crack in the board) could cause odd behavior like this.
Except for possibly one time, I do not recall the 'flashing'
problem after the system has been idle for a while. When it does
appear, it's usually after I've been using it for a while. One
possible clue that just occurred to me: When the system has been
idle, the air near the back left vents is usually cool. Right now,
with the flashing having happened [and switched OFF/ON to get back
to a solid light] a few minutes ago, the air coming from the vent
is actually quite warm. Two points this makes to me [not a h/w
1) The fan is actually working.
2) It could be an overheating problem.
>Just some random thoughts. Looking at the hardware manual, I can't see
>anything specific (in fact, it appears that the Wi-Fi switch is actually
>part of the system board assembly, as there are no directions to
>disconnect it when removing the "base cover" (isn't that an oxymoron?).
>I wonder if indeed it is simply a bad switch, which is resisting (or
>not, in your more recent experience) current...
The 'slide switch' attached to the cover is really somewhat of a
'dummy' in that it only has a slot inside that fits over the actual
switch that is, in fact, attached to the system board. The 'real'
switch cannot be replaced nor detached. The slide moves quite easily.
It's just that, sometimes it works, sometimes it does not.