Sony LBT-D107R Operating Instructions Manual page 19

. :
Remote commander i
Symptom Cause Remedy
The remote commander does not The batteries are run down. Replace both batteries.
function.
The remote commander is not pointed Point the remote commander at the
at the remote sensor. sensor.
There is an obstacle between the Remove the obstacle.
remote commander and the unit. :
The remote commander is too far Move closer.
from the unit.