Over the weekend, I attempted to install iPhone 3.0 beta 5 on my first generation EDGE iPhone. The install didn’t work, and my iPhone was stuck with the Pink Screen of Death (PSOD). The phone refused to update to the new OS, either through iTunes or Xcode. Numerous reinstalls, power/home button dances and prayers did not fix the problem and of course there was no way to go back to OS 2.2.1. Finally, I found the solution:

Download iPhone 3.0 beta 4. You will have to Google for the location, but should be able to find it. This beta expired May 29th, but that’s okay.

Restore your iPhone to beta 4 through iTunes 8.2. Option+click on “Restore” to selected the beta 4 ipsw file. Once it’s done, iTunes will complain that your software has expired. Ignore this and option+click on “Check for Updates.” Now select the beta 5 ipsw and it will install. I think the key to this solution is that iTunes is not doing a restore of beta 5, it is simply updating your phone from one beta version to the other. Good luck!