My wife's Dell Studio 1745 recently developed a screen flicker, it would then go to sleep. I changed the "what to do when the lid is closed" option to nothing, which solved the problem for a while. More recently the screen has started flickering again and will sometimes switch off (with the computer remaining on). I figure it's to do with the lid closing mechanism thinking the lid is closed. With the screen off, applying a magnet around the area of the mouse buttons (in line the the magnet location above the screen, will soemtimes fix the problem, or at least cause the screen to flicker on for a moment.
Question is, does the Studio 1745 use a reed switch for detecting the lid closed, or does it use a chip and the Hall effect? If it's the former, I've seen someone who has previous posted saying they've just removed the switch altogether, obviously the screen doesn't turn off even when the lid is closed but it fixes the problem. Whatever is causing the problem, it's very intermittent - I've had the laptop on for 6 hours today and the screen is fine (apart from it flickered during booting). Whereas last night when she turned it on, it started flickering after only an hour or so. Connecting to an external monitor doesn't help either, it flickers at the same time as the main screen (seeminly even if I try and set the laptop to external monitor only).