My HL 3150CDW shows a paper jam in tray 1

I had a double paper jam, tray 1 and rear rollers, cleared both as per instructions, but it still shows paper jam in Tray 1, but there is nothing there. Have removed tray and everything and flap that opens to fix a jam and there is nothing, tried resetting back to Manufacturer's setting, but it does not do anything. Any suggestions please as this is brilliant Laser printer and I can not afford to change it