From the top the 13 connections are
1 NC
2 GND
3 GND
4 button 3 & 6
5 button 1 & 4
6 button FM AM
7 right column button common
8 left column button common
9 button INFO & CASS
10 button MODE
11 button 2 & 5
12 LED Backlight
13 orange LED