I'm having an issue with a 9500 which won't boot (507 error, LED flashing, reboot cycle) and which I can't reload the OS on using the Crackberry nuked BB guide.

After the initial "unknown device" appears and I click next I get an error about Apploader not being able to connect. Any ideas how I can get around that? I've also tried JL Commander with no luck. Have the latest version of Desktop Manager and BB OS installed, Win 7 x64 and no SIM is in the device if that makes a difference. Any thoughts are much appreciated!

try doing this :

Select the one which says USB:UNKNOWN

* If you do not see USB:UNKNOWN or USB:BBPIN, then follow instructions listed in a1-a5:

a1) Disconnect the device from the PC.

a2) Keep the Application Loader Wizard window open

a3) Remove the battery and put it back

a4) While the red led is on, reconnect the device to the PC. The led will only stay on for a few seconds

a5) When USB:UNKNOWN appears in the drop down list, you need to immediately select Next