I’m glad I helped you fix your device. You were right about holding down the Volume Down (-) button while connecting the device to your computer. I had wondered why I couldn’t repeat the procedure by doing another soft-reset while connected. After seeing your post, I tried holding down the Volume Down (-) button while connecting the device to my computer and I got it recognized as an STMP3600 again.
To get the “Player Recovery Class” driver, I let Windows XP’s “Found New Hardware” wizard connect to the Internet and find the driver automatically. Unless you are using an older version of Windows, you probably could have done the same thing.
To summarize, here is the revised debricking procedure:
(1) While holding down the Volume Down (-) button, connect the device to your computer.
(2) If a “Found New Hardware” window appears for an STMP3600, let Windows connect to the Internet to find the “Player Recovery Class” driver automatically. If you can’t do this, obtain the tool mentioned in Peyotero’s post and repeat step (1).
(3) Run the firmware update utility for the Sansa Express.
