T23 Battery Wont Charge

[twillingham]

I recently purchased a t23 from someone who told me that he always used the docking station and rarely removed it from same. When I got the t23 home it had 80% on battery and lasted 2.5 hrs When i tried to charge the battery nothing. It just wont charge I took it to PC place and replaced the battery. No good in fact it discharged the battery from 13% to 1 percent in 30 minutes charging So I dont think its the battery.. I went to a different shop and put another new battery in it and let it charge and the laptop would not charge the battery. I believe the old battery is good at least thats what the maxi miser program indicates with 4 cycles says. Please help what could be the problem

[rkawakami]

Defect in the charging circuity of the laptop. There's a part called an inductor on the motherboard which comes loose. When it does, you lose charging capability, although the laptop should still run off the battery. You will need to remove the keyboard and keyboard bezel to get at the part. For some more information about what and where this part is at, see this thread:

http://forum.thinkpads.com/viewtopic.php?t=64710

According to the MaxiMiser utility, what is the "Full Charge Capacity" value (on the same tab as the number of charge cycles, near the middle of the window)? If it's near the "Design Capacity" value (about 38Wh) in the "Information" tab of the MaxiMiser program, then that means the battery is in fairly good shape.

[twillingham]

Thanks for the quick reply I will tear it down and take a look and let everyone know what happened. Thanks again

[twillingham]

I have your grid of the motherboard I retrieved it from www.rkawakami.net/ibm_t2x/mobo_top_72_legend.jpg Can you tell me where the inductor is located is it G6?

Admin edit: Corrected URL

[rkawakami]

Yes, that's it. It should have a "150" marking printed on top. See if it's loose by gently trying to lift it up. If so, remove it from the board, clean both metal contact points on the bottom (scraping it with a small screwdriver works pretty good) and then re-solder it back to the board. That part can be a little difficult since the solder and surface it's supposed to mount to is being covered by the part itself. I first melt a tiny amount of solder on both terminals of the inductor and then when the part is sitting on top of the board, heat the sides (where the metal comes up along the side and wraps over the top edge of the inductor).

[poshgeordie]

I think the grid diagram should be http://www.rkawakami.net/ibm_t2x/mobo_top_72_legend.jpg

The inductor for the charging cct is round black object at top centre of G6.

Also whilst there, check the associated fuse with a continuity test meter, is OK - upright rectangular object in the bottom right hand corner of the same grid.

[twillingham]

I have located the inductor however it is in place and connectedly solid

[poshgeordie]

Have you got any way of checking the fuse in the bottom right hand corner of G6 is OK?

[twillingham]

I will take a look at the fuse. Will I need a special meter of some kind to check it. In my earlier response the inductor seems to be rock solid on the MOBO could it still be bad even though its secured tightly to the MOBO?

[twillingham]

Sorry for my last post I didnt see that I will need a continuity test meter to check the fuse.

[rkawakami]

The only other way that the inductor could be the source of the problem, if it's otherwise firmly attached to the motherboard, would be an open coil winding. You can use the same ohmmeter that you can test the fuse with on the inductor. Place the leads across the top of the inductor, one on each of the metal tabs that come up the sides and wraps around the top edge. Resistance of a good inductor will be near zero ohms (put the meter on the lowest range if it has manual ranges). Anything over a couple of ohms would indicate an open coil.

If the laptop runs off of the battery okay, then I wouldn't think that the large 10A fuse being discussed here is bad. There's also a very tiny fuse next to that one which I believe protects the data input/output pin to the "smarts" inside the battery pack. Here's a picture that I posted awhile back (and shows the inductor too!):

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

Since the OP has stated that the laptop can read the number of charge cycles from the battery, that tiny fuse should be good..

The other possibility is that the Analog Devices ADP3806 chip (to the left of the photo) is defective. It's the battery charging controller.