[Q] FSL A8 topic

This is a Chinese Tablet made I believe by Okystar, based round the ATM7029 chipset which has the oddest fault. It appears to be working normally, except at boot up time. If an external device is plugged in when switched on it goes into a boot loop. This includes the power supply. With no externals it boots normally. When booted all external devices work normally.
Adb sees the tablet as an emulator. If I veiw the logcat file (ie adb logcat). the file is displayed then the command window locks up with no command prompt.
Has anyone any ideas?