DVD drive activity usually goes hand in hand with hard disk activity, the LED may simply not work for your drive...
But the LED indicator was previously working with the HD Its a Maxtor Hard Drive with its own LED underneath I don't know if that has anything to do with it Do you believe that the Hard Drive is the problem?
With its own LED? Do you mean an external drive? As far as I know, no internal hard drive has ever had an LED attached to it.
Its a Maxtor D740X-6L 40 Gigabyte hard drive, the LED is under the hard disk on the pcb. The above is a picture of the drive, but unfortunately it doesn't show it with the LED lighting up. The LED on the hard drive works whenever i access data from the drive