I have a Lenovo ThinkPad T-420, and it appears to be in good condition. (I found it in my friend's garage and he said I could have it!) But even with a "good" working battery?...or plugged in with a "good" working power adapter it won't power on. its as if there's no power to the device even though there IS a good battery and power supply(and I know the battery and power supply are good because I have ANOTHER T-420 that they came from!) )Its not a bad looking laptop, and I would like to use it, but if its not working I don't know what to do next. Can anyone shed some light on this issue for me? Or is there someplace I ca ship it to be repaired?

⟐ Answered March 06, 2026 at 8:46 MST

is it whether the slot is fake or there is other problems with it

⟐ Commented May 15, 2020 at 12:36 MST

• Keyboard has some dying keys
• Motherboard has a damaged Ethernet jack (probably repairable; I already looked into the cause; ~3.4 ohms on the orange coil and 193.3 for blue)

Basically, the keyboard has problems with the I key, primarily (other keys are dying as well) and the Ethernet is damaged. I can repair both problems and get the computer back in working order but before I do that, I need to test the SSD and rule out hidden motherboard damage. The problem I am having is the system lags for ~30 seconds at random. It doesn't do this all the time but it happens a fair amount.

I installed the SSD shortly after I bought the laptop because the drive it came with (WD5000BEVT) had problems, was 7 years old and had ~13.2k hours. I still have it, but the drive is never going back into use because of the pull reason. What I had to hand when it failed was a 240GB Crucial M500 I bought on Black Friday a few years ago and barely used before shelving it. It has 97% life left and 2,926 hours on the clock, so it's still a very new drive. Here is a picture of the SMART data aqnd Crucial Storage Executive:

⟐ Answer accepted May 12, 2017 at 13:21 MST

• i5-2520
• iGPU
• Manjaro linux

Ever since I bought the laptop I’ve had issues with the external speakers. Initially, they would work for a few seconds when messing with the audio controls before they cut out, now they don’t function at all. According to the volume controller, it’s detecting headphones being plugged in when there’s nothing plugged in at all. The external speakers are listed as “unavailable”.

Things I’ve tried

• Upgrading kernel to 4.18
• Changing linux distros (I’ve tried Antergos, Manjaro, Ubuntu, Fedora, Mint, and Elementary)
• Uninstalling and reinstalling audio drivers
• Cleaning out the headphone jack with a qtip and alcohol
• Replacing the speakers.

Something I noticed when I first opened it up was that someone probably spilled soda on it as some of it ended up on the motherboard. Really unexpected for a Thinkpad as they have drainage holes through the keyboard. I’m thinking maybe something related to the external speakers was damaged?

Thanks in advance!

⟐ Answered September 23, 2022 at 3:02 MST

⟐ Answer edited October 09, 2018 at 9:22 MST

⟐ Answered April 14, 2025 at 21:07 MST

⟐ Answer accepted May 03, 2024 at 9:27 MST

I cannot figure out what is causing this. So far, I've tried the following:

• Replaced the original battery to determine if it was an issue with the battery. This was not successful.
• Disconnected the CMOS battery in an attempt to clear any errors (with the main battery also removed). This was not successful.
• Tried several other power adapters to see if the power adapter was to blame. It was not.
• Powered on the laptop to see if an issue with the charging port was the problem (the laptop uses a barrel plug). It worked as normally when the computer is run without a battery.
• Visually inspected the charging port with the back cover removed. Nothing looked out of the ordinary.

Does anyone have any other suggestions I should try that might resolve this issue?

⟐ Commented November 18, 2023 at 21:41 MST

It randomly n repeatedly disables my internet.

At times i show ‘Available Connections, yet No available Wifi.

That is Troubleshooter only tells me the obvious.

Your ethernet is not plugged.

That would make sense when im sitting at The Coffe Shop wondering why i have a choice to manually turn on wifi. (Why was it turned off)

The drop down says.

Manual

Restart in 1 hour

Restart in 1 day

Etc…

What are thes choices and why are the here instead of “Choose Wifi conecction".

Thank You.

⟐ Answered September 09, 2019 at 19:58 MST

As of now, I have tried the following fixes:

• Heatsink removal (dusting purposes)
• New TIM (Artic MX-4)

Neither of these fixed it, so I took the keyboard off to get an average on how hot the heatsink measures vs. what the computer reports, and this is why the readout is highly suspect.

Before I mention the readout from the measurements I took without the keyboard, this is what I get with Aida64:

As far as measurements from the heatsink itself, this is what I get with an IR thermometer:

• Vent: 57.6-67.8c
• Rear vent: 60c
• CPU plate: 61.2-66.6c
• Heatpipe: 35.2-52.4c

I have also measured it with a thermalcouple and did some datalogging from my multimeter, and this is what I got:

CPU plate:

• 32-53c

Heatpipe area 1:

• 42-49c

Heatpipe area 2 (opposite side measurement)

• 42-48c

CPU vent:

• 52-55c

⟐ Answer edited October 16, 2018 at 13:08 MST

lenovo laptop t420 not support 4gb ram and not open laptop

⟐ Answer accepted July 05, 2017 at 6:53 MST

Overcoming the Lenovo T420 laptop Windows boot manager genks boot menu display problem (not entering Windows)

⟐ Edited March 06, 2026 at 20:15 MST