Monitor goes blank if run from battery

Hi,
Does the computer still run or it switches off together with the monitor?
If its still running,check the monitors power cable and make sure its well fixed.
Check the VGA cable connections.You can disconnect and then connect it again.

Thanks!

Have you connected to an external monitor, just for fun? Try that, don't run off the battery, in fact, take the battery out. Use only the ac adapter for power. Now boot pressing f1 repeatedly until you get into bios. Just let it remain in the bios screen for a few minutes, long enough to prove you don't have a hardware problem such a s the inverter going out, etc.
Then allow it to continue to boot to windows. If it appears on the external monitor (may need to hit Fn+F5 or F&, to utilize both monitors), but not the system monitor, it's possible you've got a bad piece of hardware such as an inverter going out, or even the backlight failing.
If there's no image on either monitors, but you hear the usual sounds of windows booting up completely, it gets tricky.
First think is to update to most recent bios.
Floow the directions from the Lenovo site for the T20. Use the floppy image; it's just easier.
Good luck.
Let us know how it's going.

hi there !

-if you switch the computer on and it boots up and you hear the windows sound, this could be a possible video problem or motherboard problem
-run the diags on the LCD, while the computer is off, press and hold "D" then press power button at the same time, if you see the colors red blue green without any problems then it is a motherboard or video card problem
-another method to run the test is while the computer is off; preess and hold Fn then press power button, let the test run; when you see the question were colour bars displayed, press N, if you see the colors red blue and green without any problem then it is a motherboard problem or video card; otherwise it is an LCD problem
-to toggle display on the external monitor press Fn then F8

cheers !

try to connect laptop to an ext monitor if you will still be getting this problem. if yes uninstall and resintall the video driver. if not then LCD might causes the problem. try reseating the LCD cable if possible.

Check the display power settings in Control Panel.

It's possible the video card is burnt out from over heating.If it is you need a new motherboard.

Try taking out the hard disk, plug in power and see if you have a display on your screen or external monitor. if same thing happen, try taking out the memory card. If you hear a beep sound it's a faulty mem. card, if no beep sound appears I suspected it's a motherboard faulty.

nope, battery can die even if always on AC power with battery installed. Time to replace the battery. sorry for the bad news.

Two possibilities: The display is a power hog. It's possible that the battery is failing, and has enough power to run the PC, but not the PC AND display at the same time. You would need to replace the battery, in this case. Or, in Control Panel, in Performance and Maintenance, in Power Options, there should be settings somewhere for the display when on battery or AC power. Make sure that the one for Battery doesn';t turn the display off after 0 minutes.

Are you running XP?