Is the drive jumpered correctly? I'm having trouble with a replacement A3000 drive that I think is due to bad jumpers. Check the data and power cables for faults, too.
How does the motherboard/disk module look? Any damage? Make sure there's no battery leakage and lastly, check some other functions of the machine to make sure Paula's not toast (audio, some joystick operations I think).
Oh, and Welcome to Amiga.org!
