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I have a broken ThinkPad T61. It ran hot and died while on AC power. When I attempted to boot it, I got the BIOS message "Fan error." I'm assuming that something got too hot and broke as a result of the fan dying.

Now I cannot run the machine on AC power or charge the battery. However, when I use a battery charged by another computer, the machine runs with no apparent problems. I guess the machine could overheat since the fan is broken.

Am I right in assuming that the fan broke, or is something else going on? What can I do about it?

UPDATE: After the laptop cooled down and it was dropped on the floor (that part was unintended), it can again run on AC power. Fan is dead, that is for sure. I am starting to doubt that there ever was an AC problem, but it was just the BIOS that blocked for boot since fan would not spin (fan error outputted to screen).

So fan needs replacement. Found this guide:

http://www.insidemylaptop.com/replace-cooling-fan-lenovo-thinkpad-t61-laptop/

Whether or not AC will continue to work, only further use will tell.

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migrated from stackoverflow.com Mar 15 '11 at 16:27

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Does it run on AC if the battery is not installed in the laptop? Or will it run on AC if the battery from another laptop is installed? Also, have you tried using the AC adapter on another laptop. Just a couple troubleshooting things to help you narrow it down. But either way, unless you repair the fan, it will just happen again no matter what else you fix. –  BBlake Mar 15 '11 at 16:32
    
Good questions BBlake, that actually more or less does lead to the conclusion. Yes, it runs on AC and on battery. Also on adaptor from other computer. And, true, the fan needs to be replaced. Posted a link to a guide into the question above. –  Tillebeck Mar 16 '11 at 8:25

2 Answers 2

As of about 4 years ago (maybe more now? I'm starting to get old :( ), the European Union enacted some new rules about using lead-free solder in computers. As a result, many manufacturers now just use this across the board, even in the U.S. where it's not yet required.

Unfortunately, the new solder isn't quite as soft and pliable as the old was. I've seen a lot of laptops in the past couple years where the solder holding down the power cord connector has become brittle and disconnects from the motherboard as a result of the constant small movements from connecting and disconnecting the cord and stress on the connection provided just by the weight of the cord while it is plugged in. Heat increases the rate of failure here, as it makes the solder more brittle, not less (up until the melting point, anyway, and at that point you have other problems).

This explains both symptoms: you can neither run nor charge via AC power. You'll know if this is the problem if your power cord is loose or wobbly while plugged in, and if getting the cord in just the right position allows your laptop to charge again.

To work around this, I've known a couple people who got an external charger and tried to just work via battery. I don't recommend this option. Batteries have limited charge cycles, and if you run from them constantly you'll soon have a useless battery. Instead, you'll want to find a shop that can re-solder the connection. This can be tricky, as a lot of places are reluctant to work on laptop hardware directly in the first place, and soldering is becoming a rare skill. But look around and you should be able to find someone who can do this for a reasonable price.

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Thanks for the info. Maybe that is why I got three labtops from the t40's with a loose graphic chip!... A common problem I can telle from the post on the internet on just this issue. Boot ok, run for a while, then freeze –  Tillebeck Mar 16 '11 at 8:23

The internal power supply probably broke when you overheated. That's what switches between power cord and battery to power the laptop. It is usually part of the motherboard, so you probably have a total loss.

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Actually, in a ThinkPad this might be the AC input connector which is actually a separate piece, and fairly easily and cheaply replaced at that. (I forget the exact name for it but it's easily found in any hardware maintenance manual.) –  Shinrai Mar 15 '11 at 16:48
    
It could be that as well, yes, but the connector itself doesn't have much to fail when overheated. Overheating generally fries transistors and/or capacitors. –  Hyppy Mar 15 '11 at 16:56
    
@Hyppy - That's not how I read it...I read it as 'Battery will not charge, machine will not run with battery removed' so basically 'the machine acts like the AC adapter isn't plugged in'. –  Shinrai Mar 15 '11 at 16:57
    
@Hyppy - Doh, you edited as I was posting. I don't know much about the internal construction of the bit in question but I have seen these fail due to environmental problems so I assume there's some weak solder points or something (I used to do support for Lenovo). –  Shinrai Mar 15 '11 at 16:59
    
Sorry for the edit :-) You could be right, though. –  Hyppy Mar 15 '11 at 17:04

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