Support in other languages: 
Showing results for 
Search instead for 
Do you mean 
Welcome to the Lenovo Community

Welcome to the Forums!

Welcome to Lenovo's Peer-to-Peer Discussion Community!
Please note our guidelines. How to register and login and Community FAQs.
Shape the Future of PCs

Help Lenovo Shape the Future of PCs

Take the ownership survey. Share your ideas with our product team
Community Spotlight

Visit the Lenovo Blogs!

Check out the ThinkPad Time Machine
Visit the Community Spotlight Blog
Windows  10

Are you ready for Windows 10?

Get to know Windows 10
Visit the Windows 10 Support Center
Fanfold Paper
Posts: 1
Registered: ‎10-19-2010
Location: Melbourne Australia
0 Kudos

System choking up when AC power is connected




I have a Lenovo Thinkpad edge 13 with,

windows 7 32bit,

intel i3 cpu,

u7300 @ 1.3ghz,

4gb ram,

SSD primary.


Occasionally the machine slows down to the point where it's unusable, the mouse pointer also stutters and you can see the gui rendering slowly. 


If I can get task manager process list or sysinternals process explorer open then whichever process has focus seems to be using cpu flat out 50% (100% of 1 core), so when viewing taskmgr or procexp they appear to be flat out on the cpu.


I have now noticed that there is a relationship between this and connectiopn of AC power. If I disconnect AC while the system is choking, the system will suddenly speed up and work normally again.  I have never noticed this happening while the system is running on battery.  Often only a short time after connecting AC, this problem will occur.


I suspect that this is either a kernel mode power management issue or an issue with intel cpu power modes.


I have tried selecting different modes (maximum performance, maximum battery life, video playback etc) in the lenovo power management console but this has not made a difference to the problem.


Someone please help me as this is beyond the scope of my troubleshooting abilities.


...Btw also I have noticed that full screen video appears to be dropping a lot of frames which seems crazy in 2010 on a machine like this, that may or may not be related so I thought I would mention it. Also I need to improve that, but that is a secondary issue.









What's DOS?
Posts: 1
Registered: ‎01-19-2011
0 Kudos

Re: System choking up when AC power is connected

I have ThinkPad Edge 13'' Intel u7300 and I have similar problem - my system is running really slow when laptop is charging. When I unplug AC system is running normally. The same model is for both Windows and Ubuntu OS.
My question is - does the AC adapter is recognised in proper way?
Almost the same problem was with Dell laptops.
Posts: 3,408
Topics: 26
Kudos: 429
Solutions: 259
Registered: ‎01-21-2010
Location: Etters, PA
0 Kudos

Re: System choking up when AC power is connected


run system update and see if your drivers are up to date, especially the bios.  it should be in programs, thinkvantage.  if you don't have it download it from the link and run it.  a lot of these laggy problems and slow internet are caused by an outdated bios.

T430u, x301, x200T, x61T, x61, x32, x41T, x40, U160, ThinkPad Tablet 1838-22R, Z500 touch, Yoga Tab 2 Windows 8.1, Yoga Tablet 3 Pro
Did someone help you today? Press the star on the left to thank them with a Kudo!
If you find a post helpful and it answers your question, please mark it as an "Accepted Solution"!
If someone helped you today, pay it forward. Help Someone Else!
English English Community   Deutsche Deutsche Community   Español Comunidad en Español   ru.gif Русскоязычное Сообщество
Paper Tape
Posts: 2
Registered: ‎09-02-2010
Location: Finland
0 Kudos

Re: System choking up when AC power is connected

Hello, I had the same annoying problem of cpu freezing on ac power. Today I think I finally solved it; It was the factory installed software "Lenovo ThinkVantage Toolbox powered by PC Doctor" that caused the choking. Uninstalled it, and now my Edge 13 is allright again. This was not visible in applications or processes in task manager, the cpus just were 100% all the time.

I really am amazed by this, and once again discovered the fact, that all factory installed software should always be removed when buying a new PC. All those bundle-software seems always be just crap, even if the machine is Lenovo!


Cheers, and hope this helps someone. AltGr