Hl 2040 laser printer

The paper light flashing because there is some paper inside the printer. Open the front cover and remove the cartridge and look inside for the jammed paper. Remove the jammed paper and insert the cartridge , closed the front cover and switch on the printer.
It will help you to solve the problem.

Pull the tray out and make sure the back guide is pushed against the paper. The back guide tends to move easily on these models

This usually means your printer is out of paper or there is a paper jam somewhere.

Take the toner out of the fount and you will see a little piece of paper pull that out! Your good to go!

It has toner? if not replace new one. If it has toner then try to remove the catridge and place it again. This might help you.

You may have a small jam or a piece of paper that is still inside the printer.  You may have to look for a smaller piece of paper.  I have had this happen to my laser printers before and it was because there was a plastic arm that is inside the printer that came loose during a paper jam and it wouldn't accept paper until I reattached the arm and then the printer would accept the paper.

I had this problem and couldn't figure out until I opened the front, pulled out the toner cartridge and found a paper jam.  Removed it and now I have the green light.

Damaged Rollers warranty replaced

Try shutting the printer completely down & unplug power. then plug power back in and while holding down all buttons on the printer control panel, turn it back on. this should put it into a self diagnostic mode that prints out just about everything the printer can do, including a sample page. Also, be sure all rollers are clean & trays are completely closed before restarting. If the printer works when you do this, you should most liely check all settings in the software package (driver) or perhaps reinstall the drivers. If this is necessary, be sure to download the latest drivers from the Brother website.

Try send one paper manually, then it will pick up paper from the try automatically.