Hi. The battery on my Thinkpad R31 laptop doesn't charge. I've tried 3 difference AC adapters (all of which work fine on other laptops) and 2 different batteries including a brand new one, neither of which charge. I guess I need to change the onboard power management hardware ? Is there a FRU/CRU I should replace to do this ?

Christophe Thompson

• 1224 Answers
• Posted on May 26, 2008

SOURCE: T30 2366 8GA After removing AC Adaptor battery icon shows Charging and working on AC

there is a switch in the plug end to the back of your comp its like a little swinging door that when you unplug out of back of comp this switch engages battery now if you unplug just from wall its going to see these 2 things the doors not shut but i have to keep working so it sets aside the plug still recognizing it of course but running off the battery trying to still find out why the powers not there but the plug is still plugged in and it will continually search until it reaches its falt point of dead battery
its like a battery backup for your system it gets unplug but wants to know where the power is

now in reference to the little swinging door i call it its a power over relay in your comp for some reason its not closing properly to allow battery to run by self
this is usually just a switch that needs adjusted in the motherboard configuration

SOURCE: IBM,lenovo ThinkPad R31

Maintenance manuals for both systems are on www.lenovo.com/support, under the publications section. But without looking at it, I would say no, the cables will not work.

SOURCE: Thinkpad T43 wont get any AC power

I've run into this many times with IBM machines. The power management chip on the motherboard has failed. Unfortunately, you will have to replace the motherboard in order to fix the problem.

SOURCE: ibm thinkpad no power with ac power adapter but works with battery

If prior to this it works intermittently with the AC adapter, it means the connection from the adapter power unit to the motherboard was lost and this is a typical problem with the Thinkpad. It needs a re-soldering job and not something that one can do without a proper repair manual on how to open the laptop. Try googling your problem and find out if someone has the same experience and managed to resolder by him/herself.

SOURCE: IBM ThinkPad R40 No PowerUp

If the the ram is the problem of your system, there should be a power on light on the system. indicating that some of the component of the system is not working correctly. But since you mentioned there is no light, it is the possibility that the problem is the motherboard itself.