Samsung UN46ES6500G E-Manual page 683

deleting) that access the file system of
a USB device.
If there is no USB device connected, the
TV will not record even if the scheduled
time is reached.
The TV will not record if the USB
device has no free memory space.
Check that this is not the case.
If you record a channel locked with
Channel Lock, the PIN input window
will appear when you try to play back