Here i'm running an octo-soundcard on the RPI-2B.
I tried starting to record from the octo soundcard but it doesn't work

The soundcard appears into the alsamixer, so there must be some basic communication.
arecord -l
**** List of CAPTURE Hardware Devices ****
card 1: audioinjectoroc [audioinjector-octo-soundcard], device 0: AudioInject-HIFI cs42448-0 []
Subdevices: 1/1
Subdevice #0: subdevice #0
For example i tried to record with:
sudo AUDIODEV=hw:1,0 rec -c8 -r48000 -b16 -t raw --buffer 32768 test.dat
Input File : 'hw:1,0' (alsa)
Channels : 8
Sample Rate : 48000
Precision : 16-bit
Sample Encoding: 16-bit Signed Integer PCM
In:0.00% 00:00:00.00 [00:00:00.00] Out:0 [ | ] Clip:0 rec WARN alsa: Input/output error
rec FAIL sox: `hw:1,0' Device or resource busy: Operation not permitted
In:0.00% 00:00:00.00 [00:00:00.00] Out:0 [ | ] Clip:0
Done.
Then i started to search for hardware issues and measured some voltages. Searched for bridges between some pins and so on.
I measured the 1.2 V ref voltage as well as 3.3 V and 5.0V and also i can measure the 49.15 MHz oscillator signal. On all of the GPIO Pins i can measure constant logic levels 0 / 3.3 V but no clock signal for example.
This may be a suspicious sign: I can measure the current consumption of the RPI. When connecting the power supply and booting it consumes 220 mA (here using a 12V>5V DC/DC converter with 80% efficiency. Current measured on the '12V' level). The main IC (CS42448) is getting slightly warm. But when trying to record from the octo the current consumption suddenly drops to 150 mA and the IC is getting cold! After a reboot the current consumption is still 150 mA. But when shutting down the RPI and the power supply, the powering on and booting, then the current consumption becomes 220 mA again.
Does someone have an idea? Eventually there is a overcurrent protection triggering? So what causes the intensive current consumption?
And not to forget, dmesg tells first:
dmesg | grep octo
[ 7.404037] audioinjector-octo soc
but later it tells:
bcm2835-i2s 3f203000.i2s: I2S SYNC error!
bcm2835-dma 3f007000.dma: DMA transfer could not be terminated
Any ideas? Your help is apprechiated.
Regards, Stefan