Hi Adrian,

On 2/17/2011 4:07 PM, Adrian C wrote:
On 17/02/2011 22:35, D Yuniskis wrote:

Since this is such a common remedy for ThinkPads,
I started wondering what the actual *reason* (cause)
behind it might be.

Try here

http://forums.lenovo.com/t5/T61-and-prior-T-series-ThinkPad/T23-won-t-power-up-with-good-battery/m-p/230682
and also the thinkpads forum.
http://forum.thinkpads.com/viewtopic.php?f=28&t=87401

Some good speculation & answers given

Thanks, but these describe a different type of problem(s).

Each time I have encountered a "powerup problem" on a
thinkpad, the symptoms have been:

Disk light flashes (less than one second) when power
button is pressed -- no other activity is noticed.
A second press gives the same result. Holding
power button *down* makes no difference, etc.

The behavior is the same whether plugged into AC
power or running on battery.

If you unplug the unit, remove the battery pack
and lean on the power button for a while (I hold it
for 20 seconds) and *then* plug in the AC power, it
boots right up and runs WITHOUT PROBLEM for hours/days.
You can then install the battery while it is running.
Then, disconnect power. Etc. I.e., the battery is
fine, the AC adapter is fine, the laptop itself is
fine (once it has powered up).

BIOS is at the latest revision, etc.

It is as if something has a charge on it that must be
dissipated before the normal reset/startup will work.
I seem to recall this behavior often begins when the
laptop has been left on AC power (yet powered *off*)
for a prolonged period. I will start noting the various
conditions in which the problem presents itself.

Which prompted a web search for a schematic (so I
can see what *might* be going on when this happens).
Of course, no luck on that score...

I have a schematic for the similar T23 I could mail you.

What's the difference between T23 and T22 (I guess I can
go googling... : )

Thx,
--don