SoulHeaven the Logic-Sunrise forums, introduces a new AP2.5 bypass for 360′s with dash version 12611.

This means that consoles updated with 12611 that have Liteon or Benq drives which currently do not read the games like Fable III because of the new AP2.5 checks, are now able to read them.

This hack requires the use of the x360SED v1.0 chip created by SoulHeaven and will be sold within a few days exclusively on Logic-Sunrise and Librasoft Store.

The principle is simple:

- Install the x360SED chip between the 360 mainboard and the DVD drive, solder the one wire from the x360SED to the consoles sync button
- Install Fable III on your console’s hard drive (From an original or a backup)
- Insert the game Fable III until it is recognized by the dashboard (Image of the game while taking the square)
- Press the sync button to eject the game Fable III
- Insert an original game Xbox 360 (Any), press again and the sync button controllers
- Press A to start the game Fable III starts without worries.

Obviously this is not safe for use on Xbox Live

Just a word of warning on the sed “disc swap”, although this passes the timing check, ap25 also returns data from its check which will be wrong with the wrong disk and will get you banned!
source - Bypass AP2.5 with x360SED v1.0 chip « DARKFiB3R – Wasting time since 1978