DIAGNOSIS The automatic oiler system is clogged, typically at the bar oil port, or the oil channel is blocked by sawdust.
FIX Unplug the saw. Remove the bar and chain. Clean the small oil hole on the bar where it mounts to the saw and the matching oil port on the saw itself with a pin or compressed air. Reassemble and test.
IF THAT DIDN'T WORK The oil pump itself may be faulty. Run the saw (without cutting) over a piece of cardboard or bare ground. If no oil flings off after 30 seconds, the internal pump may need service.
HEADS UP Never run the saw without bar oil, even for a test. It will ruin the bar and chain in seconds due to friction heat.