It sounds like a driver issue. You might try reverting the driver back to the previous state and see if you can get your picture back up. The monitor is working properly - to some degree - because it's able to show the BIOS. It sounds like the problem begins when the monitor loads past Windows and is unable to detect it at that point.
Also, you might want to check to make sure you're displaying in resolutions that the monitor can support.
My monitor, a Samsung Syncmaster 2443BW has been acting quite strange lately and i don't know what to do with it.
When i start up my pc the monitor goes on and shows the motherboard screen and bios information. After that the monitor flashes in the left upper corner: Analog / Digital and the screen goes totally black (before windows is started up). A few seconds later the blue led (power) goes flashing and the monitor turns off.
No matter what i do, i can't get the monitor to stay on, and what does this mean analog / digital?
I just reinstalled my OS (windows xp x64) and installed the driver from the samsung website (i selected digital on the setup). The pc worked fine on another monitor (before this, haven't checked with one after). The monitor also worked fine when first connecting it again with the pc, but after reboot i got and still get this...
I am running on a duo-core, windows xp x64, Ati Radeon HD 4870 X2 with drivers and ati catalyst completely up to date.
I would really appreciate any help or comments on this,