My Plextor PX-760A drive is failing me. I use it externally, on my MacBook Pro (intel core 2 duo), over firewire 400, in an enclosure originally shipped with a PX-750UF (not a true plextor, as most of you will know). I swapped that drive for the 760A, and it always worked fine. I used the drive almost exclusively for ripping audio CDs with an application called XLD. With XLD the 760A was a great improvement over the 750UF in terms of speed.
The past couple of days I've been ripping some DVDs with MTR4 (straightforward 1-on-1 copies in ISO disk images). Those I wanted to burn using Toast Titanium 10 on DVD+R DL disks (am using the recommended media for the 760A: Verbatim 8x disks). The first couple of disks went fine. No problem burning, and the disks play fine on my DVD player.
However this morning, after successfully burning an ISO image to a DL DVD disk, the party was over: the drive won't burn anymore. I tried burning directly out of OSX using Disk Utility, and also with another 3rd party app (called "Burn"), but all fail to burn the ISO image. Around 8 coasters later, I am nowhere near closer to a solution.
Sometimes there are error messages ("unstable interface"). Mostly, there are none. After clicking "burn" in Toast, the LED on the 760A keeps blinking orange at different speeds for a long time. Then it turns green and the drive starts humming as if doing a proper burn. But nothing is happening in fact. Toast has become unresponsive by now (must force quit, as aborting the burn doesn't release the drive anymore). After force quitting Toast, the 760A doesn't respond anymore either. I have to power it down, and take out yet another coaster after pressing the button on the tray when it's restarted.
Another big disappointment is that ripping audio CDs has become terribly slow compared to the days before this nightmare started (about half the speed i would normally get using XLD).
The downside of being on a Mac is that I don't have the option of performing diagnostic checks with PlexTools Pro. I did mount my drives in a Windows XP machine to upgrade the firmware of my 760A to the latest version (1.07). Plextools seemed to be able to to a Write transfer speed test resulting in burn speeds up to 16x on some Imation disks that happened to be at hand. Don't really know how to do proper testing or interpret results anyway.
What can be causing these problems? Did the chipset on my firewire enclosure fail? Something wrong with my MacBook? Or is the drive dead?