X41 Tablet help needed

[thinkpadinside]

Hi guys. My first post on this forum, and im sorry its not a happy one. My X41 tablet has quit charging or operating on its battery. However, it cannot be the battery since maximiser reports that it *IS* holding a charge. Battery is saying "No activity" and charge on it has been steadily decreasing. My worst fear it that its a motherboard issue. I have little money, and I would like this fixed as cheaply as possible. Somebody on the lenovo forums pointed to a possible blown fuse. Will this be repairable able by me? If so, how would I go about doing it? Even though im 15, I have soldered components back onto thinkpad motherboards and gottem them working again. However since this is a fuse, shouldn't it pop out just like any other fuse? I cannot afford to shell out a 100+ dollars on a new motherboard. Any help/tutorials and advice will be most appreciated!

[rkawakami]

Welcome to thinkpads.com!

I haven't yet opened up my own X41t but almost all of the other Thinkpads you see in my signature, I have opened before. They all have what's called surface mounted fuses firmly soldered onto the motherboard; that is to say, none of them are in sockets that you can simply extract and replace with a new one. The typical technique to replace a blown surface mount fuse is to actually solder the new one right on top of the old. Usually the metal end caps of the fuse extend all of the way to the top so that it provides both the electric contact and a means to solder another one on. Here's a photo from a T23 motherboard which shows a couple of fuses:

http://www.rkawakami.net/ibm_t2x/main_fuses.jpg

The fuse would be testable by connecting an ohmmeter across the terminals. 0 ohms will indicate a good fuse, while anything more the a couple of ohms would mean that the fuse is blown. However, even if you identify that you have a bad fuse, one problem would be figuring out what current rating it has. Generally, there's a letter or number marking on the fuse itself. If you can find that, it might be possible to determine the correct replacement part. Some people will simply buy a duplicate motherboard and grab the same fuse off of that board, but that can be a costlier procedure. Some threads I've posted to before can possibly help identify what you need:

http://forum.thinkpads.com/viewtopic.php?f=29&t=68975
http://forum.thinkpads.com/viewtopic.php?f=28&t=71618

Be aware that in addition to a blown fuse, the lack of charging can also be due to other components (inductor, MOSFET, battery charging controller IC, etc.). A loose inductor can also result in the lack of charging. Look near the battery terminals for a black "square" like the one in the fuse picture with the "150 N21" printed on top; yours may have different markings but probably looks similar.

[thinkpadinside]

Wah thats a wealth of info. How would I pinpoint the problem? Where can I buy the fuse (Walmart, radioshack, bestbuy, homedepot, etc)? Would it help if I took pictures of specific things before I opened the laptop?

[rkawakami]

Definitely not any one of those places. If you read through the two threads I've supplied earlier, you'll see that mouser.com and digikey.com both usually stock the line of Littelfuse fuses (what I'm betting that the X41T also uses on the motherboard). Since there are no schematic diagrams available for these systems, it's a matter of using your eyeballs to find the fuse(s) (generally will be identified by a letter/number combination like "F2" printed near it on the motherboard; "F" for fuse and the number following indicative of which one it is on the board). Then use an ohmmeter to test the fuse. If all of the fuses that you can find test out okay, then look for any loose inductor. Most likely it (and the fuse(s)) will be located near the battery terminals. Also look for any obviously burnt or damaged parts.

Use the instructions in the Hardware Maintenance Manual to take the system apart. Keep track of where each screw/part came from and you shouldn't get into too much trouble.

http://www-307.ibm.com/pc/support/site. ... MIGR-60073

[thinkpadinside]

Sounds like a weekend project to me. My dad has a multimeter, can I use that to test the fuses? Will the computer have to be running in order to test them? Is there any risk when testing them, or should I just go and get it repaired somewhere else? Can we also rule out the battery being bad? I appreciate your information. You are quite helpful!

[rkawakami]

Can be the motherboard but could also be your battery. Check the HMM for instructions on how to measure the voltage at the battery terminals (page 41). System must be OFF and disconnected from any power source (AC and battery) when attempting to measure the fuses. If you're not sure about what you're doing, then I'd recommend that you either have a friend knowledgeable about electronics do the work (and it needs to be a good friend in case something bad happens when he/she does the work ) or take the system to a professional (much $$$$). Your earlier statement about you being able to solder components back onto a Thinkpad motherboard gave me the impression that you know how to work a multimeter and have some basic knowledge about electronics.

If you're not comfortable about taking the system apart and poking around, then I can recommend that you try another battery or try your battery in another system. A battery will probably run around $40 or so off of eBay. If you can get somebody you know in your area to lend you one for a few minutes, that would be even better. That will at least confirm your initial guess about the problem being inside the laptop.

[thinkpadinside]

The system I referred to was my T30. I had knocked of a CPU capacitor near the processor, and soldered it back on (blame it on the fan design, the capacitor was stuck in it :/)
Unfortunately, im the only one in the neighborhood who runs an X41 Tablet. No battery sharing to go around. I will pay the HMM a visit and see what happens.

EDIT

I have opened up my X41T, and took a look around the inside. I looked specifically near the battery contacts area, and found nothing that seems to be out of place. I did not test with multimeter, I was just eyeballin it. There were no discolored fuses, just a little discolored solder (i assume this is normal). Everything seemed firm and solid. None of the fuses were blacked out or busted. The black cap things all looked like they were sitting firmly in place. I need more advice please! I don't feel too confident in soldering something that small if that is the issue. The capacitor I soldered back on had easy contact points. These things are just way to small for me. Also, if anybody lives around richmond area (specifically henrico), and has an X41 tablet battery I could borrow to test to see if its the battery or my motherboard, please let me know asap! Thanks in advance!

[thinkpadinside]

UPDATE!
I have tested all fuses near the battery contacts, and all checked out to be good and working! So does this mean my battery is the problem? Maximiser does report it as condition red, and PC Doctor reports no issues with the system board. Should I go ahead and buy a battery?