there must me a key/button thet gets pressed when u close the lid.. locate that and push it manually for a few seconds.. may be this will help..
also check the power adaptor.. it might not pe providing good quality power to the laptop...hence the display trouble.. there could be overheating issues too(with the LCD chip) feel the lcd all around and find the hot area if any on/behind the screen.
i have a Compaq Presario v2000 series based laptop and it has a small button on the top right of the keyboard that turns off the monitor...
but there will be trouble that this button just turns off the power to the backlight of the laptop screen and does not switch it off...(just like in cellphones)
get a software like powerstrip, i think it must be having shortcuts to screen saver n stuff..let me go google
take a look at: (google->shortcut to power off monitor)
hopefully something above will solve ur problem.. i searched everything on the net.
Kool.. do tell me if u solve ur problem and my advise is insted to look for a way around try and find the root of the trouble.. u might fry/damage ur laptop if somethingis wrong with ur power supply...if u dont have an extra power adaptor go to some hardware retailer and ask him to let u test ur notebook with a new one before u buy it..
i looked at ur product here
use this battery test by compaq(lol it says ur battry life should be 300 charge cycles / 1 year)
Battery health center(callibrating ur battery)
wew!!! that was a lot of stuff....