A13-Olinuxino with mod-gps

[bizarre]

hi all.

I got a trouble with mod-gps with olinuxino-a13 rev e.

I connect a MOD-GPS in UEXT near UART1 and it is not powered on (I have red light on, but it is no reaction on pwr button press)

I connect a MOD-GPS in UEXT near UART0 and try to use example: A13-OLinuXino-WIFI-MOD-GPS-LOGGER
- so I run GPS2.py and it is no serial output from GPS on screen (and in file too), and when I change ttyS0 with ttyS1 I have an error.

cat /dev/ttyS0 - prints nothing
cat /dev/ttyS1 - got an error.

I have a debian image on 4Gb SDCard

what I doing wrong?