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[T440p]What is going on with the connector for the AC jack?

Posted: Sun Aug 18, 2019 4:23 pm
by DucatiThumper
When my T440p is on the AC and gets around 60C, I smell a burning smell coming from the left exhaust vent. Inspecting the laptop I notice no burnt components. But the connector for the AC looks like this Image

The laptop is still under On Site warranty. But I have replaced the thermal paste on the cpu, likely voiding the warranty. Dont know if that is true or not.

Re: [T440p]What is going on with the connector for the AC jack?

Posted: Mon Aug 19, 2019 1:40 am
by RealBlackStuff
Refreshing thermal paste does not void warranty.
Unless you made an unholy mess of it, with too much paste, that is now all over the place! (assumption, not accusation)
What brand paste did you use?
Also, check that that AC-cable is properly connected to the mobo.

Re: [T440p]What is going on with the connector for the AC jack?

Posted: Mon Aug 19, 2019 2:51 am
by WarhawkCZ
This can happen when connector pins oxidize. Increased rezistivity causes power dissipation and heat. (I assume that I see a melted housing of the connector). It is important to change both parts of the connector as soon as possible. Your warranty should be OK. You can typically open thinkpads without voiding the warranty.
Good luck!

Re: [T440p]What is going on with the connector for the AC jack?

Posted: Mon Aug 19, 2019 5:09 am
by DucatiThumper
RealBlackStuff wrote:
Mon Aug 19, 2019 1:40 am
Refreshing thermal paste does not void warranty.
Unless you made an unholy mess of it, with too much paste, that is now all over the place! (assumption, not accusation)
What brand paste did you use?
Also, check that that AC-cable is properly connected to the mobo.
Arctic MX4 2019. Its non-conductive. I think I did a better job than Lenovo to be honest. They used an unholy amount of paste.

I checked the AC cable and its properly seated. That was my first thought as well.

Re: [T440p]What is going on with the connector for the AC jack?

Posted: Mon Aug 19, 2019 5:12 am
by DucatiThumper
WarhawkCZ wrote:
Mon Aug 19, 2019 2:51 am
This can happen when connector pins oxidize. Increased rezistivity causes power dissipation and heat. (I assume that I see a melted housing of the connector). It is important to change both parts of the connector as soon as possible. Your warranty should be OK. You can typically open thinkpads without voiding the warranty.
Good luck!
Yep the top of connector housing looks melted. Thank you for the info. Ill be contacting Lenovo. I assume that means they need to change out my motherboard?

Thankfully the warranty left is on site, so it should be done fast.

Re: [T440p]What is going on with the connector for the AC jack?

Posted: Mon Aug 19, 2019 3:12 pm
by DucatiThumper
WarhawkCZ wrote:
Mon Aug 19, 2019 2:51 am
This can happen when connector pins oxidize. Increased rezistivity causes power dissipation and heat. (I assume that I see a melted housing of the connector). It is important to change both parts of the connector as soon as possible. Your warranty should be OK. You can typically open thinkpads without voiding the warranty.
Good luck!
Notice in the pictue the wire is routed under that metal bracket. Further investigation, it was touching that metal bracket. The wire has that protective black sheath but I doubt it was suppose to make contact with that. My guess is that was the cause? I never messed with that wire, nor did it look like a previous owner messed with the internals.