Hi.
Yes I killed my BB and after joining this forum and a quick education in BBism,
I attempted to revitalize my 7105t with advice from here:
ReInstall OS When Computer Won't Recognize The Device Is Connected

I downloaded the following device software and the Desktop manager from T Mobile's website:
7100M_PBrER4[1].1.0_rel556_PL1.8.0.154_A4.1.0.377.exe
40119dt.exe

I can't get the app loader to go past the Attempting to reconnect to the JVM stage where it fails with the message:

Unable to complete the loading operation
Unable to reconnect to the device during a multi-stage load operation.

Before starting the app loader I go to the "Connection Setting" and I see a USB port and a pin number listed.
Soon as I start the app loader during the Connection setting selection part the pin# is replaced by Pin-Unknown. Is this a clue?

After my screwup upon putting the battery in I was getting Error 400. After failing this reloading operation, now I'm getting 507 with a tiny dialog box nside a cicle with a slash through it. The tiny box has thre shapes in it(circle, square, triangle)

Any advice where to go from here.
I've repeated the reloading operation 5 times in a row and nothing but failure.

Help

FM

507 just means there is no OS on the device. Not sure what's causing the loading operation to fail. It could be a computer issue...make sure you're not connecting to a usb hub. It could be a device issue (get a new BB.)

Have you tried this:

How do I wipe the BlackBerry using Jl Cmder? - BlackBerryFAQ

and then this:

What to do next if Jl Cmder will not connect and wipe - BlackBerryFAQ

Wiping with JL Cmder (the first link) simply gets your device to the 507 screen. I suggest using the second method and see if that will reload the OS to the device.