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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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#1
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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 |
#2
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The common ThinkPad powerup problem
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 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. -- Adrian C |
#3
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The common ThinkPad powerup problem
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 |
#4
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The common ThinkPad powerup problem
On 17 Feb 11 at group /sci/electronics/repair in article (Adrian C) wrote: Hi Adrian, I have a schematic for the similar T23 I could mail you. please ship me a copy to 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 |
#5
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The common ThinkPad powerup problem
Wolfgang Allinger schrieb:
On 17 Feb 11 at group /sci/electronics/repair in article (Adrian C) wrote: Hi Adrian, I have a schematic for the similar T23 I could mail you. please ship me a copy to I own a T21 with a dead display. A lot of notebook schematics can be found he http://www.reepair.net/en/forumdisplay.php/30-Laptop-Schematics HTH Reinhard |
#6
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The common ThinkPad powerup problem
On 19 Feb 11 at group /sci/electronics/repair in article (Reinhard Zwirner) wrote: A lot of notebook schematics can be found he http://www.reepair.net/en/forumdisplay.php/30-Laptop-Schematics HTH 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 |
#7
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The common ThinkPad powerup problem
Wolfgang Allinger schrieb:
On 19 Feb 11 at group /sci/electronics/repair in article (Reinhard Zwirner) wrote: A lot of notebook schematics can be found he http://www.reepair.net/en/forumdisplay.php/30-Laptop-Schematics HTH Not really Anyhow THX This Account Has Been Suspended Hhm - still works here wonder. Greetinx Reinhard |
#8
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The common ThinkPad powerup problem
On 20 Feb 11 at group /sci/electronics/repair in article (Reinhard Zwirner) wrote: Wolfgang Allinger schrieb: On 19 Feb 11 at group /sci/electronics/repair in article (Reinhard Zwirner) wrote: A lot of notebook schematics can be found he http://www.reepair.net/en/forumdisplay.php/30-Laptop-Schematics HTH Not really Anyhow THX This Account Has Been Suspended Hhm - still works here wonder. 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 |
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