Me -> bricked vortex also
like you, I managed to brick my vortex, with all the same symptoms. I really hope someone has a solution to this.
My phone symptoms: Phone powers on and goes straight to the white LG logo on black background. It never progresses beyond that point.
What I did to cause this:
1. I rooted my phone with z4root. That worked OK.
2. I installed "ROM Manager"
3. Tried to backup my current rom. "ROM Manager" said it needed to install "clockwork recovery" rom, and then offered me a list of recovery roms.
4. I had no idea what I was looking at, so I randomly selected one. (Yes, I'm acutely aware of how idiotic that was, and I wasn't drunk either, which makes it that much worse).
5. When the phone rebooted, BRICK. (per above symptoms)
I've tried:
1. Hard reset: "Vol down + home + power". This does absolutely nothing to change the symptoms. No recovery modes, etc.
2. Pulled the batter out and left it out for 2 days while I wallowed in my own self disgust, and tried the reset again, to no avail.
3. Booted my laptop into ubuntu, plugged the phone in via usb, and issued "dmesg" command. It looks as thought linux doesnt register anything plugged into the port at all.
4. In windows, in device manager, nothing shows up resembling the phone, and there are no "unkown devices" listed.
5. Installed adroid sdk on my pc, ran "adb devices" from CMD prompt, and no devices were listed.
So, help, please! I'll find a way to buy a beer for the guy/gal who solves this problem, lol.