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The common ThinkPad powerup problem

Hi,

I was handed an old T22 that "wouldn't power up". I immediately tried the unplug, remove battery pack, hold power depressed (for a long time), plug in power and was able to get it to boot (no surprise there).

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

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...

So, anyone have an *informed* idea as to what is going on (and, therefore, a worthwhile direction to pursue a long-term fix!)?

Speculators need not apply... :-/

Thx,

--don

Reply to
D Yuniskis
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Try here

and also the thinkpads forum.

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Some good speculation & answers given :)

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

--
Adrian C
Reply to
Adrian C

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.

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

Thx,

--don

Reply to
D Yuniskis

Hi Adrian,

please ship me a copy to snipped-for-privacy@gmail.com I own a T21 with a dead display.

THX

Saludos Wolfgang

--
Meine 7 Sinne:
Unsinn, Schwachsinn, Blödsinn, Wahnsinn, Stumpfsinn, Irrsinn, Lötzinn.
Wolfgang Allinger   Paraguay             reply Adresse gesetzt !
ca. 15h00..21h00 MEZ  SKYPE:wolfgang.allinger
Reply to
Wolfgang Allinger

Wolfgang Allinger schrieb:

A lot of notebook schematics can be found here:

HTH

Reinhard

Reply to
Reinhard Zwirner

Not really :( Anyhow THX

This Account Has Been Suspended

That happened yesterday also with another .net account which revieved after 24h. So let`s wait.

Saludos Wolfgang

--
Meine 7 Sinne:
Unsinn, Schwachsinn, Blödsinn, Wahnsinn, Stumpfsinn, Irrsinn, Lötzinn.
Wolfgang Allinger   Paraguay             reply Adresse gesetzt !
ca. 15h00..21h00 MEZ  SKYPE:wolfgang.allinger
Reply to
Wolfgang Allinger

Wolfgang Allinger schrieb:

Hhm - still works here .

Greetinx

Reinhard

Reply to
Reinhard Zwirner

Heute gehts bei mir auch wieder.

Today it works again for me. They had a little trouble with .net accounts.

Saludos Wolfgang

--
Meine 7 Sinne:
Unsinn, Schwachsinn, Blödsinn, Wahnsinn, Stumpfsinn, Irrsinn, Lötzinn.
Wolfgang Allinger   Paraguay             reply Adresse gesetzt !
ca. 15h00..21h00 MEZ  SKYPE:wolfgang.allinger
Reply to
Wolfgang Allinger

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