Check the link LEDs

First, check the CPRI board on the Tiogapass, the port where the fiber link is connected should have a green LED above it. If it is red, it means the cables are not properly plugged or there is a driver issue. If it is off, then it means you plugged the fiber to the wrong port (only three are active, those which have the LED on).

Check the cables

Please try switching the fiber optics.

Check the driver

Check if the board is recognized:

lspci -vvv | grep Swallow

Check the service status:

systemctl status rmu

systemctl status swallow

screen -x lte

If the LED is green

Get RF RX and TX levels

You can get more details about the RRH with the RMU:
sudo screen -x rmu

Then (if the RRH is plugged on swallow port 0):

swa:0/port:0/node:0 info -r

There you will see the RF Tx and R level.

SSH to the RRH

For more debugging, you can connect to the RRH through SSH:

ssh user@192.168.127.10 (password: 4fgd6AE7)
> radio -t transmit -p