I had a problem similar to this a couple of weeks ago. Unfortunately a few more details would be appreciable if I'm to be of any help.
1) All the IDE HDDs i've encountered use jumper pins to identify themselves as slaves, masters, etc. to the BIOS. Did you look at the the jumper table and properly slave the drive to your master boot disk? This would cause Windows not to recognize the presence of the disk. (I suppose it assumes at boot that this other drive is a seperate master boot disk for another OS.)
2) During start up or shut down, did Windows run chkDsk? This is usually seen before your login screen... it asks if you want to skip it with the space bar and then goes through the process of verifying the disk. When I allowed this, I accidentally let the PC believe that this disk I was repairing was the new master disk. Following this it wouldn't POST.
3) Is the BIOS running at all? You say the screen is blank, but is there even a blinking cursor in the top corner of the screen or is there no video output at all?