Troubleshooting with matrices

You may order the capes pcb/octoscroller.* from iTeadMall or Seeedstudio. You'll get a batch of 10. As the cape is large you have to order 10x10cm (about 19$ + shipping). Buy some 2x8 IDC-Headers, pin headers and a 74LVC/HC245. That will reduce the pain of wiring.

Some Parts of the display flicker or have a constant color/colors missing

You may experience something like this (JPx):

1. All okay
2. Upper okay, lower just flickering red
3. Upper okay, lower no blue
4. Same as JP 3
5. Upper shows just constant blue, lower nothing
6. Upper nothing, lower constant green
7. Upper constant white, lower just green
8. Upper just green, lower okay

If that's what you see: your HDMI is still active. The method mentioned in Setup.md may not work or you simply ignored it. You can manually fix it by editing /boot/uboot/uEnv.txt and removing the # from the line that says optargs=capemgr.disable_partno=BB-BONELT-HDMI,BB-BONELT-HDMIN. Warning: pay attention, that you're not editing the line with BB-BONE-EMMC-2G. This will disable the eMMC too.

Check by using bin/identify.