how can I fix my homelite d3850b chainsaw?

I have been using my saw up to today without any problems.My bar oil is not lubricating my chain and bar anymore.Ive taken the bar and chain off and cleaned the hole with an air compressor where the oil is dispursed but still nothing.Ive drained all the oil and looked inside the bar oil tank and hose and filter are still attached.Does anone know the problem?