Support in other languages: 
Showing results for 
Search instead for 
Do you mean 
Paper Tape
Posts: 2
Registered: ‎01-10-2012
Location: St.Thomas, Ontario, Canada

X61T A/C Adapter or Motherboard Problem?


I have a late-production X61T that is still under its' four-year warranty for another few months.


Lately I've noticed a strange anomaly with the charging system and processor speed.


Issue number one arises when I use different Lenovo A/C adapters.  The only way I can get the processor to run at it's top speed of 1.6 Ghz is to use a 90W 20V 4.5a A/C adapter.  If I use the original 65W 20V 3.5a adapter, the processor throttles its' speed back to between 800 Mhz and 1.1 Ghz.  I have a half-dozen Lenovo power supplies, and the issue is the same with any and all of them.


All BIOS and Win 7-x64 power settings are set to maximum processor speed with no power-saving features enabled.


Issue number two is the battery that won't charge.  It has consistently remained at the 13% level for the last month and will not charge. The laptop dies when the A/C adapter is removed, it will not run at all on battery power. I have another battery on the way to test.


My question is, are the two problems possibly related to the power/charging circuits, necessitating a motherboard replacement?


Any help/opinions/suggestions appreciated.


Thanks. Regards.








Posts: 7,626
Kudos: 759
Solutions: 802
Registered: ‎11-23-2007
Location: USA

Re: X61T A/C Adapter or Motherboard Problem?

Welcome to this forum, old friend...:smileyvery-happy:


The issue of  *61 series ThinkPads not running at full speed with a 65W adapter has been well-documented, and points to a bad battery.


For the time being, I'd remove the battery altogether so the charging circuit doesn't get damaged.



In daily use: R60F, R500F, T61, T410

Collecting dust: T60

Enjoying retirement: A31p, T42p,

Non-ThinkPads: Panasonic CF-31 & CF-52, HP 8760W

Starting Thursday, 08/14/2014 I'll be away from the forums until further notice. Please do NOT send private messages since I won't be able to read them. Thank you.
Paper Tape
Posts: 2
Registered: ‎01-10-2012
Location: St.Thomas, Ontario, Canada

Re: X61T A/C Adapter or Motherboard Problem?

Hi George.


Thanks for the welcome to the forum!  I've always just kinda perused this board without ever registering.


I was going to PM you about the power problem, but I know you are a busy man these days, so I thought I'd give a shout here.


Thanks also on the battery info for the X6-series.  Kinda threw me for a loop when I saw it happen the first time.  The tech who replaced the screen suggested it might be a charging problem with the board, and since it is still under warranty, to get it replaced.


Of course when my replacement battery arrives :smileyhappy::smileyhappy: I'll be able to verify the problem either way.


Thanks.  Regards.




Posts: 2,505
Registered: ‎03-19-2009
Location: Idar-Oberstein, Germany

Re: X61T A/C Adapter or Motherboard Problem?

If the new battery is well, the described problems are gone.


Additional info:

The CPU-speed problem you described concerns to all newer ThinkPad models starting from T/R/X60. If the wall power is not enough, the CPU "pulls" additional power from battery. In case of damaged or missing batteries the CPU keeps the lower speed until a good attery will be attached or a 90W power supply will be used.

My home-forum:
Wiki: Deutsches ThinkPad-Wiki English ThinkWiki
My ThinkPad-Collection