IBM thinkpad t41 screen goes blank after being used for about 5 minutes. Could it be a motherboard issue?

I concur with what Diegotech stated.

To iterate further;

1) The DC Power Jack (DC IN), may have cracked solder joint/s on the motherboard connector, (Female), where the DC Power Jack plugs in.

Resolder

2) The DC Power Jack may be broken.
Center Pin mount, and/or body of DC Power Jack, and/or Outer Shell mount.

Replace DC Power Jack.

3) Wires from the DC Power jack plug to the female connector on the motherboard, may be bad.

Replace DC Power Jack.

Two examples, of a place to buy an IBM ThinkPad T41 DC Power Jack,

1) http://www.buy.com/prod/dc-power-jack-connector-socket-for-ibm-thinkpad-t40-t41-t42-r50-r51-r52/q/sellerid/23962916/loc/101/215782035.html

2) http://www.machinaelectronics.com/store/buypart/IBM_Thinkpad_T41/DC-P001

Past this point it's a bad DC sensor on the motherboard.

Replace motherboard.

IBM ThinkPad T41 Service Manual, (Free),

http://www.tim.id.au/blog/tims-laptop-service-manuals/#toc-ibmlenovo

On this page go down to the 8th line.
The one that starts with > ThinkPad T20.

Go across, and click on > T41

Takes approximately 2 seconds to see the first page, and additional time to fully download.

Page 142 for 14.1 inch LCD screen
Page 151 for 15 inch LCD screen

(PDF file page number box at top)

There is no problem in your motherboard. In your motherboard, clean your ram and also where ram is put. Then restart your system again it will work. When it will not work please change your ram. Then it will work.

If your computer is still in warranty, you can call IBM support at 1-800-426-7378. If the system is already out of warranty and if you want to purchase the part (motherboard), you may call the IBM Parts Department at 1-800-388-7080 or 1-866-428-4465 (then select option 3).

This is a common problem with IBM Thinkpad T40, T41, and T42s. They develop video issue due to over heating.
If you want a temporary solution put some pressure the mouse buttons just below the keyboard and right above the touch pad. Press firmly with your palm when you start the laptop and the display should come back on. Or hold the laptop with your four fingers underneath and thumb on the mouse pad and lift it up so that there is pressure at the point where your index & middle finger are. This will improve the contacts of the chip that is causing the graphic card to malfunction.

We fix these issues all the time. However, it is not something fixable by the end user as it needs professional repair equipment and expertise to get the job done right as it is motherboard level repair.

The cost of this repair is relatively cheap now for IBM T40/T41/T42. It should cost you roughly $80 to $120 to get it fixed (in metropolitan area, in smaller towns repair shops will rip you off). If you are quoted more, then shop around.

We provide complete laptop repair service www.laptopmart.ca
Tech tips for laptops you may find useful: http://www.laptopmart.ca/techtips.html

the board level soldering might be worm out for memory chip or the graphic chip. Latop does have hot issues. When it is in use, try not to move the computer. always close the clamp shell and use both hand to handle the notebook when it is in use or when it is still warm.

The chip soldering problem can be resolve by locating a local board level repair shop or technicians. It is not that difficult with experienced technicians or shops.

could it be a screen saver, or the unit is going into hibernation.

with a multimeter verify if you have power in inverter, if not, try to connect the inverter to another power supply for testing.

Connect an external monitor, press F7 to switch displays. If all is good then the video card is ok.

It's a common problem with flex of the unit causing the video chip to coming un-soldered from the motherboard. It's possible to repair but very difficult requiring luck and specialist equipment.

http://answers.yahoo.com/question/index?qid=20070710050433AAgGOTJ

Saw exactly the same think on another t41 i was trying to fix. If it was moved at all screen went off.

Turned out it was corrosion on the motherboard that was causing the problem.

Has it been liquid damaged or got damp in the past?