Power problem - ThinkPad T400 model 6475 - Win7 SP1

[Gotribigo]

Hello everyone! This is my first time on the forums. Very helpful forum!

This power problem began some days ago when plugging and unplugging the AC adapter to recharge the battery. Every time the screen went dark for a fraction of a second and then turn to the brightness I have it set to. I didn't pay much attention to it as I could keep working without any interruption.

Since a couple of days the battery won’t charge when the AC adapter is plugged but will also not discharge. I have tried it with another AC adapter with the same results. Without the AC adapter plugged, the battery will discharged as normal. Having two batteries I tried both of them, but neither will charge, one shows 74% charge and the other one shows 8% charge.

I bought a docking station to check if that would bring some solution but it didn’t solve the problem.

The laptop will only start with the battery attached, trying to start it only with the AC adapter attached or from the docking station without the battery attached I keep getting an error message "0190 critical error low-battery error".

I have been running the laptop now for the last 4 days attached at the docking station and the power AC adapter attached to the docking station with the battery that has only 8% charge and still keeps running without charging the battery and also without discharging it.
Trying to run a battery reset, gives me a message "You have to attach the AC adapter to reset the battery gauge" although the AC adapter is attached.
Since the battery didn't started to charge, the power on indicator is green, the battery indicator is orange I am using the battery with 8% charge, AC power is off but on the docking station is on.

-Reading through the ThinkPad T400 and R400 Hardware Maintenance Manual didn't help me find a solution.

-Reading on this forum haven't come across a similar problem.

-Uninstalling the Microsoft AC Adapter and Microsoft ACPI-Compliant Method Battery and doing a cold start didn't help.

-I am thinking of changing the keyboard, but I will have to buy a new one.

-Could it help taking the memory battery for a half an hour and replace it in again? - what will it do to my configuration?

-Perhaps changing the Power Jack but I don't want to have to take the whole laptop apart without solving the problem.

Will certainly appreciate your kind advice.

[RealBlackStuff]

Welcome to the forum.

Quite often this problem is caused by the Lenovo Power Manager (6) software.
If you have it, UNinstall it, then try again.
If you have access to another T400, can you try your battery in there?

Also see this: https://forums.lenovo.com/t5/tkb/articl ... icle-id/24

[Gotribigo]

Hi RealBlackStuff,

Thanks for your prompt response to my problem!

Unfortunately since my last post I run into a series of blue screens.
I then disconnected everything possible, memory, WiFi card, memory battery, etc, started testing the power on, placing back each component one at the time, until I have tested all, last I mounted the ssd back but the blue screens kept coming back, without even letting me access the BIOS.

A rescue disk didn't work, so by Monday I had nothing else to do as to format the ssd and reinstall the Win7 system again.

After the system new setup, I still get the "0190 critical error low-battery error" when starting the laptop without a battery attached, and every time I have to set the day and time on the BIOS, but with the battery attached I don't have to set date and time on the BIOS

Of my two batteries, the one which had 74% charge went at once dead, also the laptop will not boot even with the power cord plugged in, only with the one with 8% will boot and work with the power cord plugged in. I have order a new battery which should be deliver tomorrow.

I am wondering if the error is on the keyword control? perhaps a new keyboard could solve the problem, but then again this is a T400 I have had it for the last 4 or 5 years. Looking at price fall of the latest Txxx models I am not sure I want to invest more on this Laptop.

Any other ideas, or advice one this matter?
Thanks in advanced for your help.

[axur-delmeria]

Have you tried a different AC adapter?

With the symptoms your unit is having, it's either the AC adapter or the system board's power circuitry.

[RealBlackStuff]

... every time I have to set the day and time on the BIOS, but with the battery attached I don't have to set date and time on the BIOS

Looks like your (yellow round) CMOS battery is dead. Replace it.

Off topic: in the past I worked in your neck of the woods!
Back in 1998/99 as a contractor I did the Y2K programming for Hoffmann-La Roche in Kaiseraugst.
Well over 2,000 Cobol and Assembler programs had to be modified!
In those days I lived "just around the corner" in Oberwil BL.

[Gotribigo]

@RealBlackStuff, Thanks for your advice!
Yes I have thought about the CMOS battery, but it only occurs with the AC adapter. Not when the battery is also attached, so I'll wait until tomorrow to try it out with the new battery.

@axur-delmeria Thanks for your advice!
I have two AC adapters and a docking station they apparently work well. When I used the docking station I turn the laptop on the docking station power button and the power goes through, if it is a system board's power circuit, then I'll sell this T400 for parts... I don't want to go through the weariness to change the system board, which means to buy a new/used board... with the price fall on the Txxx systems I rather buy me an excorporate used recent model, meanwhile I'll keep using my old T43...


Off topic: @RealBlackStuff - well it's a small world...!
I live in Kaiseraugst, on the verge of the century I was working with Bull Honeywell host with some 500 Dummy terminals for an insurance company in Basel, mainly with COBOL programs, we even had a Bull system 6 with a punched card reader attach to it, a few months after the turn of the century the system was changed to RAID system servers, I have done very little programming with Pascal, and tried some in Formula, didn't make it to C or Java... sinf, sinf.... afterwards made the MCSE and worked from the early windows for work groups till windows 2000 as Pc / Server Supporter... "the good old times!".

MOD edit: there's no need to change the text-size of posts or PMs!
It's only the making/editing of posts/PMs where the text-size is larger than normal, due to a forum-software glitch.
Hopefully fixed one of these days...

[RealBlackStuff]

A main-battery keeps the CMOS-data up-to-date, even if the laptop is off. AC does not.
Proof that your CMOS battery IS dead!

[Gotribigo]

A main-battery keeps the CMOS-data up-to-date, even if the laptop is off. AC does not.
Proof that your CMOS battery IS dead!

Thanks for the clarification, I'll replace it.

[Gotribigo]

Have you tried a different AC adapter?

With the symptoms your unit is having, it's either the AC adapter or the system board's power circuitry.

Coming back to your support, the AC adapter seems to work OK, as I reinstalled the system. As far as I recall a new installation run only if the laptop is attached a AC adapter and not only on battery, besides this is the only working battery and it show 8% charged, the other lost from one moment to the next the charge 74% and is completely dead.
If I decide to go ahead and try to fix the board's power circuitry, what does it take? how should I go about it? do I need to replace the mother board?
Thanks in advanced for any further advice.

[Gotribigo]

A main-battery keeps the CMOS-data up-to-date, even if the laptop is off. AC does not.
Proof that your CMOS battery IS dead!

I have now replace the CMOS battery and it works, Thanks.

The power problem is still unresolved.
The new battery that came with 80% charge. I am now down to 15% as I've used it without a the power cord plugged in, but it won't charge when the power cord is plugged in.
Unplugging the power cord while running, it will turn off the laptop; although the battery is attached; and only with the power cord plugged it wont start

I just bought a T510/i5/4GB-RAM/160GB from ebay for 135 bucks, I would like to fix the T400, but only if for parts I don't have to give out more than 50 bucks, if not possible then I'll tried to sale it for parts.

Thanks in advanced for any advice on this issue.

[RealBlackStuff]

Complete T400 machines and parts are dirt-cheap on eBay USA.
Check prices on eBay.de (or ricardo.ch).
Look for "motherboard, planar, mainboard, platine" or whatever they call it there.
If a part comes from the EU, ask a colleague/friend in Grenzach or Weil, to order it for you and have it shipped to them, to save you import duties.