T41 - Do not charge battery -motherboard replaced and solved

[fje]

Hi, folks. A friend of mine call me for help. His T41 do not charge the battery at all. Feeling that the problem was related with the battery (he uses to work with the laptop connected to the mains, but without taking out the battery) he ordered a new one via eBay.

Once the new one came, he inserted in the laptop and found that the new one, even having 75% of charge, didn't charge either. He was blaming the seller and in the way of returning the battery to him. At this point he called me and I asked him for doing some tests before returning the battery and he agreed. After these tests done, I came to the position that the new battery was OK (you will see) and that the problem could be in his T41, but not being able to go further I now ask you for some help in order to be able to do a better diagnose.

Here is what I did:

1.- I came with my T42 and put the NEW battery in my T42, and it began to charge. So, the new battery seems to be OK.
2.- I put my battery in his T41 and it didn't charge. So, it seems to be a problem in his T41
3.- I measured the voltages between the different connectors of the battery IN the T41 and IN the T42 and all of them were equal, so, it seems NOT to be a problem of the T41 hardware.
4.- I found that even disconnecting the mains adapter and leaving the T41 with only battery, the battery icons were always saying "charging - 70%" and with the icon of the main power adaptor connected. So I felt it could be a problem of the power management driver.
5.- I tried to download the last PM driver from Lenovo web site (quite different of the IBM used to be ), I did it with the driver, the special driver for XP and the Battery Maximizer User Interface, tried to install all of them but the driver installation told me that there was a more recent version installed, so I canceled the driver installation.
6.- In one of these installations and reboots the icon with "battery like" icon that indicates in green the percentage of battery charge was gone out.

Then , my questions now:

a.- Could I be right in thinking that the problem could be more software/driver related than Hardware related? Is any other way to more accurately confirm it?
b.- Where could I find the most up-to-date power management driver to install? Should I install it even over the "more recent version is installed" message? Which drivers/sfotware should I really install?
c.- I was trying to find a software similar to the Power Management PWMUI.exe I have installed in my T42 with Windows 7 (6ju410ww - it seems to be Win7 only), does it exists something similar in functionalities for the Windows XP SP3 that my friend has in his T41? Where could I find it?

The details of the laptop of my friend are:

T41 - 2373-2FG
Windows XP SP3

Thanks for any help.

Javier

[RecTech]

Hi Javier

This sound to me like the charging circuit in the T41 is broken, the way to test this would be to totally discharge your working battery from your T42, insert this into the T41 and leave on charge (no need to start up the laptop), if after a period of time say half an hour, the laptop does not boot from battery only it is safe to say the charging circuit in the T41 is faulty.

[fje]

Hi, thanks for your answer, even those aren't good news

This was my first feeling, but when I found the same voltages than in my T42, I saw light of hope.

The answer to your suggested test is we already did it, using the T41. We totally discharged the battery, then we put the power adapter (laptop in shutdown) all the night. No charge at all. So, it seems you should be right.

An additional thing I found today. After having worked with the T41 and the power adapter, if I do shutdown, take off the power adapter, insert a charged battery, after 4-5 seconds the green light of battery in the cover of the T41 lights on. (it shouldn't being the laptop in shutdown mode, should it?)

Then several questions: Do you feel it can be repaired? What cost could it be (price of reparing vs a T41 balance)? Can you do it or do you know any one that can do it?

Thanks and kind regards.

Javier

[poshgeordie]

Hi again Javier. Good to hear from you and hope everything is fine in sunny Spain!

The battery charging function is basically independent of software and operating systems etc, and will charge when the laptop is powered down but still connected to AC mains, so I would suggest going back to basics and forget about any "software problems" until you're 110% certain the hardware is OK.

The usual problems are the Charging Chip which can burn out, and the battery fuse.
There's a circuit somewhere on the forums and a copy is here.

Should help with fault finding.

[fje]

Hi, Nick, nice to read you again.

Thanks for your answer, that, unfortunately for my friend, I have to agree as I did with RecTech, specially after having discover that the battery light remains lighted when the laptop is switched-off and the mains not connected.

So, still my question, do you feel this can be repaired and that the cost it can imply worth the possible current value of the T41 laptop?

Javier

[poshgeordie]

So, still my question, do you feel this can be repaired and that the cost it can imply worth the possible current value of the T41 laptop?

It is possible to repair it if the fault is one of the major chips, but there are many tiny components any one of which could be faulty.
Personally I would only change the charging chip and check the major FET Chips, and do no more even if it's still faulty.

What would be the cost of such a repair? Changing the charging chip and doing the other checks is around an hour's work.

Is it worth it? That is only your decision, but there's no guarantee the above repairs will fix the problem.

[fje]

Bick, tried to send you a PM, but systems seems not to work properly, so, I sent you an e-mail. Please, have a look to it if you are able to....

regards.

Javier

[fje]

Got a PM from the US offering me a refurbished motherboard and after talking to my friend, he will take the risk of having me trying to repair his T41 with this motherboard.....

Javier

[fje]

Yes, I changed the title of this topic. I got from the US (Dominic) a mtherboard refurbished in the UK (Nick), and being my first laptop motherboard replacement, I was succesful.

Now the laptop is working, no screw is missing and the battery charges as it is supposed to do.

Now I have an spare T41 motherboard that doesn't chrage the batteries, but is working anyway. Anyone interested on it?

regards.