Mailing List Archived Message #350

From: "Lewis G Rosenthal" <> Full Headers
Undecoded message
Subject: Re: [eCS T60/T61] 'Rapid Flashing' WiFi LED indicator on TPad T60
Date: Tue, 24 Feb 2009 22:11:06 -0500
To: "eCS ThinkPad T60/61 Mailing List" <>

On Tue, 24 Feb 2009 20:00:59 -0500 (EST) "Carl Gehr"
<> wrote:
>OK, you said skip some... So, I'm at the bottom!
>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.
1) Change of BIOS firmware/embedded controller firmware;
2) Oxidation on battery contacts;
3) Loose/oxidized AC connectors;
4) Stress crack;

Some firmware revs alter voltage requirements, thus what might not be an
issue under one rev becomes an issue under another (when, for example,
voltage is reduced to lower overall power consumption, & oxidation might
have already lowered voltage to minimum tolerance *beforehand*).

>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.
Have you tried reorienting the unit on its side or even upside down?
Applied mild pressure in alternating corners (careful!!)?

>>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.
Or a crack which expands & contracts with the temp change...

>>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.
IOW, a royal PITA!!!


Lewis G Rosenthal
Rosenthal & Rosenthal, LLC
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