4 G-drives stop mounting simultaneously via FW (usb still works)

Hello there,
in a bit of a crisis here and I have a really weird problem that just doesn't make any sense.

I have 1 G-RAID, 1 G-RAID mini, and 2 G-DRIVEs.
I usually work with 3 of them chained/linked together via FW and coming into my FW400 port of my macbook pro (pre-FW800).
The fourth drive (G-DRIVE) is for my music and I just have it connected via USB, so it's not really part of my problem - YET!

I can't remember the exact order of events, but today one of the drives just failed to mount, so I went into Disk Utility, which gave errors both on verification and repair: not repairable.

I take out the drives and plug them into another macbook pro, trying both FW400 and FW800 ports, and using new cables in case the others were faulty, but the results are the same.

After trying a different combination of things it turns out that the other 2 drives are suffering the same symptoms. Except that now none of them even appear in Disk Utility.

So I try connecting them via USB and they all work fine. I run Disk Warrior: G-RAID has some minor problems with its directory (the others are fine) and I get Disk Warrior to repair it. I try to plug it in again into my FW port, but still nothing, which brings me to here.

I spoke to someone at G-TECH who kept saying "UBS" instead of "USB", and who repeatedly assured me that "the firewire ports should work just fine", after which he made the astute suggestion of just sending the drives to their repair centre.

So now my fourth G-DRIVE comes back into the equation, the one that I mount via USB. I decide to try connecting it to my FW port and it behaves the same as the other 3 and just doesn't mount and doesn't appear in Disk Utility.

Is there any possible reason that can tie all of this into making sense?

I've had the following suggestions from various people:

there's a problem with my FW port on my laptop
it's happening on 2 different machines

the cables are faulty
I have used a dozen different cables

There's a problem with the FW on the drive
4 drives? ..at the same time?

If anyone can shed a light on this I'd be eternally grateful as right now this is extremely confusing and I don't know what to try as I'm desperate, with a bunch of large video projects, each with a tight deadline and a nervous client breathing down my neck.

Many thanks

I've read of several problems similar to yours, and I had a firewire mount problem with my one and only external combo drive.

From memory, the solution is quite simple - turn off the drives and unplug them completely from both the Mac and their power source. Do without them for several hours, overnight preferably. Then try them connected via firewire again.

Thanks Hugh, I really hope that's going to solve it, but I think there's something a bit more specific at play here, since it has affected all my drives at the same time.

But at the same time it could really be anything at this point, so I'll definitely give that a go.

Thanks again

It turns out that another 2 Lacie drives (which were connected to the second laptop) are also behaving exactly the same: they are powering up as normal, but not mounting via Firewire, although they're able to mount via USB.

So that's a total of 6 drives across 2 laptops.

Has this got anything to do with the electricity supply? Could something have happened to have caused them all to do this at the same time?

The firewire controllers, or bridges, are often the problem, and powering them off for an extended period resets them, thus enabling firewire once again.

Seeing you have two quite separate Macs, and each has firewire problems with external drives, there is, as you suggest, some other factor involved. A power spike might have done for the controllers, but without tests that would be hard to determine.

Have you tried changing the drive sequences, and transferring drives between the two Macs? Have you tried connecting drives individually via firewire, with either Mac?

With drives connected successfully via USB, what does System Profiler and/or Disk Utility tell you about them?