Learn how to diagnose the symptom when the computer's hard drive light remains ON continuously.
The boot drive cannot be located. This typically happens if the signal cable is inserted backward at one end.
In most cases, the hard drive light remains on, after replacing a drive or upgrading a controller.
Make sure that the cable is inserted in the correct orientation at both the drive and controller ends.
If you can not determine the problem at this point, try replacing the drive with a known good working drive. Do not forget to change the CMOS setup after replacing a new hard drive.
If still does not work, try to replace a new drive controller board.