External Drive - USB Connection Recognized, FireWire Connection Not Recognized

[davidosus]

I consider myself very good at all things Mac. But this one has me stumped.

I've just arrived home with a WD My Book Home Edition 1TB external drive. Formatted for Windows it mounted correctly via FireWire and USB.

First things first: I formatted it for the Mac... Mac OS Extended (Journaled), two GUID partition tables. So far so good. Each partition is recognized, each mounts like it should.

Time Machine then backed up my Intel iMac... again, everything's normal. No odd or unusual behavior.

Here's where things get strange.

For whatever reason I formatted the drive via USB. But my intention hereafter is to connect via FireWire... I need each USB port for peripherals.

But the drive isn't recognized through FireWire. I'm asked if I want to initialize it. When reconnected through USB the drive mounts again.

What's going on? Why is the drive recognized when connected via USB but not when connected via FireWire?

 

[pach22]

WD My Book Drive Prob Solved

Try placing the WD power supply away from the drive (a few feet). I was just up all night and tried everything (cable replacement, restarts, tapping, prayer, forums, etc.).
Hope it works.

 

[ZMacintosh]

hm, have you done a power cycle of the drive and the computer?

Try a PRAM Reset and an SMC Reset to further test if the ports might have acted quirky.

when doing the PRAM & SMC resets id recommend unplugging the harddrive form the computer.

PRAM Reset:
COMMAND OPTION P R keys all at once immediately following the start chime and before the grey screen appears.

SMC Reset:
iMac/MacMini

1. From the Apple menu, choose Shut Down (or if the computer is not responding, hold the power button until it turns off).
2. Unplug all cables from the computer, including the power cord and any display cables.
3. Wait at least 15 seconds.
4. Plug the power cord back in, making sure the power button is not being pressed at the time. Then reconnect your keyboard and mouse to the computer.
5. Press the power button on the back to start up your computer.

The iMac (Early 2006) and later models do not have a button on the main logic board for resetting the SMC, which eliminates the need to remove the computer's cover to reset it (as required for some earlier models).

MacPro

To reset the SMC on a Mac Pro:

1. From the Apple menu, choose Shut Down (or if the computer is not responding, hold the power button until it turns off).
2. Unplug all cables from the computer, including the power cord and any display cables.
3. Wait at least fifteen seconds.
4. Plug the power cord back in, making sure the power button is not being pressed at the time. Then reconnect your keyboard and mouse to the computer.
5. Press the power button to start up your computer.

Another way to reset the SMC on a Mac Pro computer is:

1. From the Apple menu, choose Shut Down (or if the computer is not responding, hold the power button until it turns off).
2. Open and remove the metallic outer door.
3. Press the SMC_RST switch that is located slightly below and to the right of the row of diagnostic LEDs. Use a non-metallic, non-conductive object, such as a wooden pencil. Note: Mac Pro (Early 2008) does not have an SMC_RST switch, refer to the reset procedure steps in the previous section.
4. Replace the metallic outer door.
5. Press the power button to start up your computer.

Unlike models of Power Mac G5 or Power Mac G4 computer, the Mac Pro computer does not have a PMU. This functionality has been replaced by the SMC.

MacBook/MacBook Pro/MacBook Air:

MacBook, MacBook Pro

1. If the computer is on, turn it off.
2. Disconnect the AC Adapter and remove the computer's battery.
3. Press and hold the power button for 5 seconds and then release the button.
4. Reconnect the battery and AC Adapter.
5. Press the power button to restart the computer

Note: Starting with MacBook Pro (Late 2008) and MacBook (Late 2008) models, you may instead use the reset method for MacBook Air (below) to reset the SMC. All earlier models of MacBook and MacBook Pro must use the method described above, which involves removing the battery.
MacBook Air

1. If the MacBook Air is on, turn it off.
2. Connect the power adaptor to a working power source.
3. On the MacBook Air keyboard, press (left) Shift-Control-Option along with the power button once.
Note: You must use the keys on the left side of the MacBook Air keyboard.
4. Wait 5 seconds and press the power button to start the MacBook Air.

Apple recommends only performing an SMC reset when the MacBook Air has been properly shutdown. This prevents issues from occurring to the file system.

http://support.apple.com/kb/HT1894



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Or if the reset doesnt work. try formatting it blank under USB disconnect, restart and plug in with firewire and see if it recognizes then....if so format using firewire and try both connections. could be a possible bad Firewire cable, and unstable port on the imac or the enclosure.

ive had some touchy ports on my external enclosure before aswell.

 

[WishingDigiJosh]

if i'm understanding correctly... your computer still sees it when it's connected via FireWire, but is asking you to initialize the drive as if it were new out of the box?

that's odd behavior, let us know if the PRAM and SMC resets help.