I've had a Packard Bell Easy One Dc laptop for a couple of years which I tend to use at home on mains power. It's performed reasonably well until recently.
Now the screen goes dark after a few minutes and I can't get it to come back on. I can just make out the display so the rest of the laptop seems to be working.
I wondered if it was something to do with the battery (which I've hardly ever used) so I tried it on just the battery after discharging and charging up (the battery doesn't seem to last long) and I tried it with the battery pack removed.
But which ever way the screen still darkens after a few minutes.
You'll first want to check out your Power Options (in Control Panel).
On the "Power Schemes" tab, check the "Turn off monitor:" setting, and maybe increase that number.
Otherwise, have you tried tilting/moving/tapping your LCD display? I have seen laptops (Dell in particular) that will 'bug out' after a while because the connection is flaky inside the computer. By rocking the LCD or tapping it, it will regain connection again.
The battery appears an unlikely source of the problem, and you've pretty much eliminated it as a possible cause.
lol @ "soda cans" (yes, they're called capacitors)
I'm not sure those are necessarily a problem on laptops as much as they are on desktops. However, I wouldn't discount the motherboard itself as a possible cause for these issues.
Is there a switch/pin that is depress when the LCD is closed? if so try playing with that a few times, press and release it to see if the screen comes back on.
If not then either the backlight on the LCD is going or your inverter board may have gone. It works at bootup but goes out after warming up one of those two would be where I start.
I didn't know Packard Smell made laptops. Can you find a link to a picture of it on line and post it? I would like to see it.