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novae-lithic
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Posts: 8
Registered: ‎05-16-2017
Location: AU
Views: 321
Message 1 of 8

T440s problems turning on

Hi, Just wondering if anyone has any insight into what the problem with my T440s is ... it went from working fine to not turning on at all. I had given up on it... but then, I found that it will turn on: (1) Only if both batteries (internal and external) are removed (2) Only if the power cable is plugged in a certain way. That is, before, the power cable (with the rectangle shape and yellow plastic) could be plugged in either way and it would work. Now it only works if it is plugged in one way - if I turn the plug upside down it down work. Furthermore, the laptop turns on immediately when it is plugged in, I don't have press the on button. Once it starts up it works normally... any ideas?
Community SeniorMod
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Posts: 9,861
Registered: ‎01-01-2010
Location: US
Views: 293
Message 2 of 8

Re: T440s problems turning on

Symptoms point to 3 different problems, which seems unlikely.  Not turning on with battery installed points to a short circuit in the battery, but power plug only working in one orientation points to a broken port.  Turning on immediately points to dead CMOS or a short in the power button.  I could do a better job of diagnosing if I could see it, but you and I are a long way from each other,


Rich


I do not respond to requests for private, one-on-one help. Your questions should be posted in the appropriate forum where they may help others as well.

If a response answers your question, please mark it as the accepted solution.

I am not an employee or agent of Lenovo.
novae-lithic
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Posts: 8
Registered: ‎05-16-2017
Location: AU
Views: 276
Message 3 of 8

Re: T440s problems turning on

Hi and thank you very much for your response.

 

The external battery is fine, it works on a different T440s and the working eternal battery from the other T440s won't work on the faulty on.

 

By CMOS do you mean the CR2032 battery? It was working when the laptop failed and since then I've removed it (but haven't replaced it yet, but the laptop starts under the conditions outlined above).

 

Do you know if the power button component is 'modular'? In that, could i find and install a replacement or is it integrated into the motherboard? But would a new power button resolve why it won't start on battery?

Community SeniorMod
Community SeniorMod
Posts: 9,861
Registered: ‎01-01-2010
Location: US
Views: 267
Message 4 of 8

Re: T440s problems turning on

The CMOS battery is the little yellow disk that plugs into the motherboard. If that is missing, it will start as soon as it is plugged in.  It should start with a working external battery, unless the internal one is shorted.  If the CMOS battery is missing, I'm not sure what will happen if there is no A/.C connected.  The power button is part of the palmrest, but there is a little modular switch that screws in from the bottom.  It can be replaced separately.  It can be tricky to get into the correct position, especially if you haven't done it before. 


Rich


I do not respond to requests for private, one-on-one help. Your questions should be posted in the appropriate forum where they may help others as well.

If a response answers your question, please mark it as the accepted solution.

I am not an employee or agent of Lenovo.
novae-lithic
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Posts: 8
Registered: ‎05-16-2017
Location: AU
Views: 258
Message 5 of 8

Re: T440s problems turning on

Thanks again for the insights.

 

Would a new power button solve the problem of not starting with either battery attached? Or the polarity of the plug? Or would they be separate issues?

Community SeniorMod
Community SeniorMod
Posts: 9,861
Registered: ‎01-01-2010
Location: US
Views: 251
Message 6 of 8

Re: T440s problems turning on

The plug has no polarity.  There are 3 connectors.  The outside face is ground.  The inside face is +20v and the center pin is connected o ground through a resistor.  The resistance indicates the capacity of the adapter.  I think your problem is more than the power button, but again, I would need to see the machine to be sure


Rich


I do not respond to requests for private, one-on-one help. Your questions should be posted in the appropriate forum where they may help others as well.

If a response answers your question, please mark it as the accepted solution.

I am not an employee or agent of Lenovo.
novae-lithic
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Posts: 8
Registered: ‎05-16-2017
Location: AU
Views: 207
Message 7 of 8

Re: T440s problems turning on (from battery)

Hi, thanks for your insights so far. By replacing the CMOS battery the laptop turns on as normal - plug in either orientation and not until the button is pressed.

 

However, it doesn't turn on without the cable being plugged in (i.e. cannot turn on from battery).

 

Once on, both batteries are recognised and have charge and I know that the external one works because I've tried it on another laptop. However, if I remove the plug while on the laptop turns off immediately - no power seems to be available from the batteries.

 

Any ideas why the laptop can't draw power from the batteries but can see them and see how much charge they have?

novae-lithic
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Posts: 8
Registered: ‎05-16-2017
Location: AU
Views: 166
Message 8 of 8

Re: T440s problems turning on

For anyone that encounters the same problem, there's a blue cable inside the T440s that runs from the power switch to a metal sheet towards the left half of the laptop (and towards the back from where the drive sits). This is held down with a small piece of clear tape. Mine had come unstuck. By replacing the tape so that the end of the wire makes contact with the metal sheet the laptop starts from battery as normal.

 

So, my T440s works as normal after:

 

(1) taping the blue wire back down with a new puece of tape

(2) replacing the CMOS battery.

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