Bizhub 3320 the paper keeps jamming from tray 1 and go under the drum unit .... how can this be fixed

Have you checked the default setting in control panel for that printer?

Do you have PF-P11 or PF-P12? follow below instructions

Check and clean the paper passage rollers (pick-up,feed and separation rollers).Clean the paper transmision roleers located before drum unit.

Follow the steps below to clear the paper jam.

1. Pull the paper tray completely out of the printer.
2. Pull the jammed paper up and out of the printer.
3. Press the cover release button and then open the front cover.
4. Pull out the drum unit assembly. Pull the jammed paper up and out of the printer. If you cannot remove the drum unit assembly easily at this time, do not use extra force. Instead, pull the edge of the jammed paper from the paper tray. To prevent damage to the printer caused by static electricity, DO NOT touch the electrodes shown below.
   
5. Open the back output tray. Pull the jammed paper out of the fuser unit. If the paper jam can be cleared, go to Step 7. After you have just used the printer, some internal parts of the printer are extremely hot! Wait for the printer to cool down before you touch the internal parts of the printer.
   
6. Open the jam clear cover. Pull the jammed paper out of the fuser unit.
7. Close the jam clear cover. Close the back output tray.
8. Push the lock lever down and take the toner cartridge out of the drum unit assembly. Take out the jammed paper if there is any inside the drum unit.
9. Put the drum unit assembly back in the printer.
10. Put the paper tray in the printer.
11. Close the front cover.

http://support.brother.com/g/b/faqend.aspx?c=hk&lang=en&prod=hl5040_all&faqid=faq00000026_010

does it get jammed from draw #2? does a4 jam in tray 1 and by pass

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/normanj_7893313f0751935f

Hi Good day!! here are the steps how to remove paper jam in brother hope it help's you!!
1. Pull the paper tray completely out of the printer.
2. Pull the jammed paper up and out of the printer.
3. Press the cover release button and then open the front cover.
4. Pull out the drum unit assembly. Pull the jammed paper up and out of the printer. If you cannot remove the drum unit assembly easily at this time, do not use extra force. Instead, pull the edge of the jammed paper from the paper tray. If the jammed paper can not be pulled out easily, turn the jam dial towards you as you gently pull the paper out.
5. Open the face-up output tray. Pull the jammed paper out of the fuser unit. If the paper jam can be cleared.
6. Open the jam clear cover. Pull the jammed paper out of the fuser unit.
7. Close the jam clear cover. Close the face-up output tray. If the paper jam still cannot be cleared, for HL-5130 and HL-5140 users go to Step 10, and for all other users go to the next step.
8. Pull the Duplex Tray completely out of the printer.
9. Pull the jammed paper out of the printer or the Duplex tray. Put the Duplex tray back into the printer.
10. Push the lock lever down and take the toner cartridge out of the drum unit assembly. Take out the jammed paper if there is any inside the drum unit.
11. Put the toner cartridge into the drum unit until you hear it lock into place. If you put it in properly, the lock lever will lift automatically.
12. Put the drum unit assembly back in the printer.
13. Put the paper tray in the printer.
14. Close the front cover.

Clear the jammed paper as follows.
Observe Cautions signs in printer.
Always remove all paper from the paper tray and straighten the stack when you add new paper. This helps prevent multiple sheets of paper from feeding through the printer at one time and prevents paper jams.
1. Press the cover release button and then open the front cover.
2. Slowly take out the drum unit and toner cartridge assembly. The jammed paper will be pulled out with the drum unit and toner cartridge assembly.
3. Pull the paper tray completely out of the printer.
4. Close the front cover.
5. Pull the jammed paper up and out of the printer.
6. Open the front cover again.
7. Open the back cover.
8. Pull the tabs at the left and right hand sides toward you to open the fuser cover (1).
9. Using both hands, gently pull the jammed paper out of the fuser unit.
10. Close the back cover.
11. Pull the duplex tray completely out of the printer.
12. Pull the the jammed paper out of the printer or the duplex tray. Put the duplex tray back in the printer.
13. Push down the blue lock lever and take the toner cartridge out of the drum unit. Clear the jammed paper if there is any inside the drum unit.
14. Put the toner cartridge back into the drum unit until you hear it lock into place. If you put the cartridge in properly, the blue lock lever will lift automatically.
15. Put the drum unit and toner cartridge assembly back in the printer.
16. Put the paper tray firmly back in the printer.
17. Close the front cover.
18. Make sure that the Paper LED is now off and the printer is ready.
After clearing paper jam if noise persist printer may need a Repair Tech and parts replacement for broken or wore parts.

Theo, remove the drum and paper tray.
Disconnect the power source.
Carefully reach under paper tray and tray to pull paper out.
Sometimes depending upon the unit, you may find a flap inside the drum area, that lifts up.
If you cannot remove the paper jamming unit, you may want to find a plastic folder, which you will need to cut the same size as the paper you are using.
Feed this in buy hand trying to free up the lodged paper.
Most of the time, its a small piece stuck in the left corner.
Good luck.

The problem may be comming from the drum unit, there is a small over sray tray right under the developer mag roller. It is mostly filled up with waste toner or dropped toner from the mag roller. You have to take out the drum unit and then the opc drum and vaccum out the tray and that should take care of the problem for now... The problem will come back..... Have you ever had the developer and or the drum & blade replaced. Minolta are a duel component copier. When the developer is worn out it will start to trow toner and fill up the small tray under the dev. mag roller..... Good Luck