My brother HL-2040 wont print and the green ready light is blinking but nothing is happening

SOURCE: BROTHER HL-2040

I think the previous post applies to resetting the drum light after replacing the drum.

You need to reset the toner end-of-life condition.

1. Open the Front cover
   
2. Press and hold the GO button
   
3. Power ON the printer while continuing to hold the GO button
   
4. All 4 LED's will light up and then 3. Once the 3 LED's are lit, release the GO button
   
5. Press the GO button 2 times. This will cause the
   LED's to light solid
   
6. With the LED's lit solid, press the GO button 5 times
   
7. At this point the Paper light should be blinking. Toner end-of-life has been reset
   
8. Close the front cover.
   

SOURCE: Brother hl-2040 printing problem

Could be that there are a mark on the drum itself or some dirt, remove the drum unit and inspect the surface , by rotating the drum , becareful not to touch the drum as it will leave marks on the surface

SOURCE: Brother HL 2040 Printing problem

ต้องการไดร์เวอร์printer hl 2040 คะ

SOURCE: won't print. blinking red paper light flashing

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

SOURCE: I have a Brother HL-2040. The "paper light is on & won't print.

Hi,
Sounds like a paper jam. There's a flap at the back of the printer-once open you should be able to see if the paper is stuck there. (Exactly the problem I had yesterday-I didn't spot it at first and it nearly drove me mad! :)
Good luck,
Raf