while upgrading the handheld software for the blackberry 7230, the restore failed and now the blackberry will not turn on, it has a picture of an app with a circle and line crossing over it and "507" beneath it.

Did the desktop software tell you the upgrade completed? Were you at the stage where the desktop software was sitting at the "connecting to device" while your BB reboot?

Did you try to pin the reset button? When I last did a 7230, the device was having a hard time rebooting and the hour glass was spinning for 10 minutes. I pinned the unit and the hour glass was still giving me about 10 minutes. I almost called it in when after a few more, it successfully started up.

Device error 507 means that the BB is not recognizing that it has an OS installed. If you can't reload it from your own PC, RIM recommends taking it to another PC that has the same HHOS installed.

Try running through Application Loader again and choose the option to NOT backup / restore - just load up the System software....