T41 no longer charging battery

[Wind_Rocker]

To make a long story short, I plugged 18 volts AC into a T41 which promptly took out the 18 VAC power supply and the T41 will no longer charge the battery.

T41 still works 100% with the IBM power supply and works from a charged battery, until the battery is drianed, just won't charge the battery at all.

Is there some user-replacable part that would obviously fail with a shot of AC current? or is this most likely a circuit failure on the motherboard that can not be easily repaired?

Thanks
David

[frankiepankie]

Maybe there is a blown fuse.

Here is a map with the location of different fuses:

http://i48.photobucket.com/albums/f228/ ... VE0012.jpg

You can check with a multimeter (on the Ohm measure setting) if the fuse is blown

0 Ohm is good, if it measures something like 1 (1 is total left on the screen of the multimeter) then it could be that the fuse is blown.

Or look for a beep setting on your multimeter, so you can hear if it conducts electricity (you should hear a beep if it conducts electricity, and if it beeps, it is good)

Good luck

[rkawakami]

Welcome to thinkpads.com!

While there are generally no user-serviceable parts on the motherboard, that hasn't stopped some of us from attempting component level repairs . I don't know exactly what the application of AC voltage would do to the system, but from the sounds of it, you only have a problem with the battery charging circuit or the battery itself. The main 10A (?) fuse that protects the battery has to be good since the laptop still runs off the battery. However, if the T41 is designed the same way as the T23 (which I've done some poking around on), there's a smaller fuse that appears to protect the pin which gets data from the battery. You should see if the IBM Battery MaxiMiser program is able to read the information from the battery. If it can, that would say the fuse is good.

The next thing that I would try would be to get another battery and see if your laptop charges that one, or put your battery into another known good T4x system and see if it charges there. If your system does not charge a different battery or your battery charges in another T4, then that points to a motherboard issue.

About 98% of the parts on the motherboard are surface mounted devices (SMD). That requires a little bit more care than through-hole devices when removing and installing components. Good soldering skills are a must, along with some circuit tracing and component identification and testing knowledge. If your problem is a blown battery charger controller, those are usually 24-pin Analog Devices parts. If you don't have any access to SMD re-work tools, then about the only way to replace something with a high pin count as that would be to cut all of the pins off at the edge of the device, individually unsolder each pin from the motherboard and then mount the replacement part.

ref: http://forum.thinkpads.com/viewtopic.php?t=37956 (Documentation on T23 motherboard components)

[Wind_Rocker]

Thanks for the replies everyone. The laptop I damaged with AC current is my old company supplied work laptop, I've been issued a new T61 and IT let me hold on to the T41 for a while in case I forgot to transfer something. I took it apart looking for the fuses after frankiepankie's reply and decided it best to leave things the way they are.

My wife loves the old T41 and takes it with us when we travel, its lighter and more reliable than our Toshiba Satelite. I've been watching eBay and won a very clean T41 for $119 + $10 shipping (sans hardrive) which arrived since my original post.

Using the new T41 as a battery charger (until 160gb hard drive arrives from Newegg) I have verified batteries are good and the damaged T41 accurately reports the battery state of charge. I then swapped the hard drive over to the new T41 and found that the new guy works perfectly, very happy with that deal.

Thanks again for the help, looks like a great forum
David