Logitech Guitar Hero controller buttons

Hi,

I'm having troubles figuring out how the buttons on my Guitar Hero controller works. I'm guessing its a voltage divider / resistance ladder, but I just can't wrap my head around how it works.

I've taken a few pictures and made some measurements. Hopefully there's a smarter person on this forum who can nudge me in the right direction ;)

http://imgur.com/a/SCH02/logitechguitarpins

Buttons Colors
1      Green
2      Red
3      Yellow
4      Blue
5      Orange



Measuring between pins:
1, 2

Resistance change depending on multimeter settings.
200M = 1.1M
20M  = 4.09M
2M   = 803K
200K = 140K
20K  = No reading

Reaction when buttons pressed:
1
2-3-4-5 // I hold all buttons down at the same time to get the same reaction as just pushing button 1//




Measuring between pins:
1, 3

Resistance change depending on multimeter settings.
200M = 1.1M
20M  = 4.09M
2M   = 803K
200K = 140K
20K  = No reading

Reaction when buttons pressed:
3
4-5




Measuring between pins:
1, 4

Resistance change depending on multimeter settings.
200M = 1.0M
20M  = 20K
2M   = 20K
200K = 20K
20K  = 19.98K

Reaction when buttons pressed:
5



Measuring between pins:
2, 3

Resistance change depending on multimeter settings.
200M = No reading
20M  = No reading
2M   = No reading
200K = No reading
20K  = No reading

Reaction when buttons pressed:




Measuring between pins:
2, 4

Resistance change depending on multimeter settings.
200M = No reading
20M  = No reading
2M   = No reading
200K = No reading
20K  = No reading

Reaction when buttons pressed:




Measuring between pins:
3, 4

Resistance change depending on multimeter settings.
200M = No reading
20M  = No reading
2M   = No reading
200K = No reading
20K  = No reading

Reaction when buttons pressed: