I have just been given a Maxtor 750gb separate hard drive but it has no power adaptor. Would i be able to use an adaptor from my 500gb Maxtor separate hard drive or will i have to purchase a new power adaptor ?

3.5drives require 12vdc at no less than 2 amp recomended 12vdc 3amp it is always best to provide more amp for hard drive keep the voltage correct 12vdc
asme adaptors work out to 4 gig drives all my Western digital drive have same power adaptor no matter the Gig size .

all external hard drives that need a power adapter use 12v

Try it on another computer. Is the blue light on the front on or blinking?

Did you disconnect the firewire drive before installing? You may need to update your firmware. Also, try these things:

1. Shut down and disconnect your firewire drive leaving nothing is connected to the firewire ports.
2. Restart, and use Disk Utility to repair permissions on your internal.
3. Shut down, and disconnect the AC power from the computer and your drive; also remove battery if laptop.
4. Let computer sit unpowered and disconnected for15 minutes.
5. Reconnect AC power to only the computer and reinsert battery.
6. Restart computer.
7. Verify that firewire ports are visible using System Profiler.
8. Reconnect your firewire drive, and refresh window in System Profiler to rescan the firewire bus, and confirm that drive is visible.
9. Repair disk and permissions on the firewire drive.

Hello,
Before trying out a 3rd party utility software,

What you should do is,

depending on your operating system,

Right-Click on 'My Computer Icon', then select

'Manage'.

When you get to Computer Management page,

Click on Disk Management on left hand side,

This will display ALL the disks installed on your system, either partitioned or not partitioned, formatted or not formatted.

Then go to the ones that are hidden, not created, or not displayed, right-click on it, then you'll see different actions that you can perform.

Also, in some instances, what you just need to do when you get to this page is to assign a new, distinct, drive letter apart from the ones already in use on the system.

This will automatically bring out the hidden drives.

Hope I have helped you out.

Goodluck

Is it still under warranty?

If you hear a click-click sound it means that your drive's mechanics ia failing. BAD NEWS !!

Power Adapter for Mactor OneTouch 4

AC Input : 100 AC - 240 AC (50/60HZ)
DC Output ( V/A ) : 12V / 3.5A
Output Power : 42W

The PSU for my Maxtor 500Gb 9NZ2A4-500 drive is 12V DC, 2A rating, 2.1mm "plug" with centre "hole" as positive.

Regards, kbsguru

Try to remove the drive and connect it directly to another computer.
If still doesn't spin up then most likely the board has failed.