iMac 24" and BootCamp Compatibility Issue: Unrecognized Hardware Problem?

Last November, we were reporting about the on-going issue faced by many iMac 24" owners unable to run WinOS via BootCamp. Despite numerous trials and SMC upgrade, it was impossible to use Windows on some iMac 24" despite Apple's claims. Hereafter is the story of Will, one of our readers, who was the unfortunate owner of a BootCamp-incompatible iMac 24".

Here is my recollection of my 24" as I remember them.
I bought my 24" iMac the day it was released (Sep 15, 2006). I spec'ed it out with the following equipments:
2.13 GHz Intel Core2Duo
2gb ram
7600GT graphics
BT Keyboard and Mouse
As soon as it was delivered I reformatted the drive and reinstalled OSX. Afterwards I downloaded and installed BootCamp. Rebooted and installed Windows XP pro without any issues. I then noticed about 6 dead pixels, defective ram, and a screen hum related to the brightness of the screen. So apple care set me up with a replacement computer. I boxed up my original iMac and sent it back. On October 2nd I received iMac #2. I went through my ritual for new computers and wiped the drive and installed the OS from scratch. I installed boot camp and rebooted. This time I got no video from the internal display. After lots of troubleshooting I hooked up my 19" Samsung. After the restart I was able to get into the Windows XP setup via the external monitor only. I finally got windows installed via the external display and decided to poke around. I saw that the windows nVidia drives "saw" the internal monitor but had it set to 640 x 480. I tried to change it to the screens native resolutions but it kept switching back to 640x480. The internal screen was on and getting power because the backlight was on. I could even control the screen brightness via the BootCamp display tool in the system tray. I was defeated. I tried different install CD's. I tried slipstreaming the most up to date nVidia drivers into the Windows install CD. Nothing worked. New versions of boot camp came and went and nothing helped. So during this time the other constant issue I was having, was the screen humming when dimmed. So I packed it up and brought it to the apple store in Woodcliff lake NJ (Tices). The machine was slated to have the LCD replaced. While the genius wrote up the paper work I told him about the BSOD when booting to windows. He became interested and said he would try to get the logic board replaced during the repair. Three days later I picked up the machine. With a new logic board. I got home and I was able to boot right into windows without even having to redo my BootCamp installation. On a side note the iMac still hums.
That’s my story.
Thanks for all your help.

This report demonstrates clearly that the current issue of some iMac 24" with running BootCamp is indeed hardware-based, and not entirely due to any firmware or software compatibility problem.
If one can not determine if the Apple tech only changed the logic board and not other components, the fact that Will could immediately launch BootCamp from scratch without having to repeat the procedure proves that the original software/application installation was fully functional, and only a hardware-related issue was preventing Windows to be displayed on the internal LCD.
So, if you are among the unfortunate iMac24" owners unable to run WinOS on your iMac24” as advertised by Apple, just write a polite letter to the Apple Support and/or Consumer Satisfaction Service for having the problem fixed, or at least the logic board to be exchanged.