How do you solve the so called "Black Screen Of Death " On an iMac Intel 27" EMC 2309 and 2374

According to various forums I've visited , this is very common issue that Apple has not addressed. I've read that it could be a logic board issue on the graphics card or a LED driver board issue or even a temp problem. My friend just got this issue resolved on her MacBook Pro but it cost her $500 to have it taken care of. This problem is making Apple look very bad in the eyes of it's customer's. I won't post some of the negative comments I've come across on these forums as a result of consumer frustration with Apple not taking care of this. Let's just say it needs to be addressed. Oh and the " Black Screen Of Death " is what people are calling it, not sure of the official problem name but it's an intermittent tendency of the display to go completely black while the OS is running fine.