My monitor goes black and flashes once or twice during start up. If I turn the monitor on and off I can see the desktop for 1 or 2 sec's before it goes black again. If I do this repeatedly it will suddenly get brighter and start working after about 3 or 4 min's. Can anyone suggest a course of action to determine if the problem is a Driver software or graphics card(ATI Radeon HD 2400 Pro) or defective monitor ? Once the monitor starts working it works fine for hours until I turn it off. Any Suggestions ?