Lenovo C940 15.6" Not Charging Correctly

[Anish S]

Hello everyone,

 

I have a Lenovo Yoga C940 15.6" laptop that does not charge correctly. When I try to plug it in, it says "plugged in, not charging". It is not on conservation mode or anything, it just doesn't charge up at all. It will be maintaining that charge only. The only way to completely charge it is to shut the computer down and then it charges to full. Lenovo has replaced the battery, but it still doesn't charge correctly. I even got a message from the BIOS when I turned on the computer saying

 

"The connected AC adapter has a lower wattage than the recommended model which was shipped with the system. To boot with the AC adapter, please connect the AC adapter which was shipped with the system.
Press Esc to continue."

 

I am using the original charger, and Lenovo even gave me another charger to try out, which didn't solve the problem. I have tried other outlets in my home and outside, but it doesn't solve the problem, which is why I believe the problem to be within the computer itself. If anyone would be so kind enough to fix this, I would be very grateful.

 

Thank you,

Anish S

[TukangUsapEmenq]

Might be the component failure on the laptop itself, it's not getting enough power to charge it while it's on, but enough juice when it's off, hence the "Plugged in, not charging". You'd also notice some performance degradation than usual with heavy use, even with it plugged in. I'd get it checked on electronic repair shop, or if it's still on warranty, RMA the laptop.

[dag_dg]

How long have you had the unit? Is it a secondhand purchase? You might try updating the bios to a newer release; a lot of Lenovos can be very finnicky about "genuine batteries" which means that a bug could theoretically cause them to mark a genuine battery as "invalid" and refuse to charge. It also might be worth comparing the wattage between the two chargers to see if there is any difference.

 

Agree with dhannemon13 though you should definitely continue to pursue the warranty where you can.

[Anish S]

1 hour ago, dhannemon13 said:

Might be the component failure on the laptop itself, it's not getting enough power to charge it while it's on, but enough juice when it's off, hence the "Plugged in, not charging". You'd also notice some performance degradation than usual with heavy use, even with it plugged in. I'd get it checked on electronic repair shop, or if it's still on warranty, RMA the laptop.

Thank you very much, I only asked on LTT forum because the warranty ran out. My BIOS is completely up to date (from lenovo vantage). I will go to a shop and hopefully it's not too expensive.

[Anish S]

1 hour ago, dag_dg said:

How long have you had the unit? Is it a secondhand purchase? You might try updating the bios to a newer release; a lot of Lenovos can be very finnicky about "genuine batteries" which means that a bug could theoretically cause them to mark a genuine battery as "invalid" and refuse to charge. It also might be worth comparing the wattage between the two chargers to see if there is any difference.

 

Agree with dhannemon13 though you should definitely continue to pursue the warranty where you can.

Hello, thank you for your reply. This is a brand new computer from Lenovo, funny enough this is actually the replacement device from Lenovo from my first computer. My BIOS is completely up to date. How do I check wattage from a charger? I have a multimeter but no idea what to put where.

[dag_dg]

The "brick" part should tell you the wattage though it may say "VAC" as the number. According to Lenovo it should be a 135W adapter which does seem like a bit more "oomph" than most smaller laptop adapters.

 

Since you're running the latest BIOS firmware normally I'd say to try rolling back but IIRC lenovo laptops are one of those situations where it is extremely difficult approaching impossible to do so.

[Anish S]

15 minutes ago, dag_dg said:

The "brick" part should tell you the wattage though it may say "VAC" as the number. According to Lenovo it should be a 135W adapter which does seem like a bit more "oomph" than most smaller laptop adapters.

 

Since you're running the latest BIOS firmware normally I'd say to try rolling back but IIRC lenovo laptops are one of those situations where it is extremely difficult approaching impossible to do so.

Yes it's a 135 Watt charger, and Lenovo gave me a 170 watt charger to see if that worked too, neither of which do. I might take it to a shop but I can manage shutting my computer down every night as I don't need it to charge that much during the day thankfully.

[dag_dg]

Yeah then it's likely either a BIOS bug or as dhannemon13 mentioned a possible component failure where it's not detecting the current properly. You might also try getting a dock for the laptop if it can use one and see if the error shows up when using the dock.

[Anish S]

1 minute ago, dag_dg said:

Yeah then it's likely either a BIOS bug or as dhannemon13 mentioned a possible component failure where it's not detecting the current properly. You might also try getting a dock for the laptop if it can use one and see if the error shows up when using the dock.

What is a dock for a laptop?

[dag_dg]

That is what a dock looks like, you "dock" the laptop right onto the dock itself and it provides power to the laptop.

 

More recently there are now thunderbolt-based docks that can charge laptops as well that plug into your laptop via a thunderbolt connector. For charging you'll want to make sure it is a dock that can provide enough power to the laptop for it to be able to charge.

[Anish S]

Hello everyone, I bring good news!! I was watching the recent LTT video about tiktok hacks and he talked about Windows + Ctrl + Shift + B to restart drivers. After I did that, my computer IMMEDIATELY started charging!! LTT saves the day!