Bottom of the copies are darker than the top I

Step 1 Check the top of your Canon fax/copy machine to see if your specific model has a protruding extension piece from the plastic delivery tray. Push the extension piece down if one is present on your model.
Step 2
Grip the bottom edge of the paper delivery tray at the front of the machine. Lift the tray upward to reveal the rectangular, plastic toner cartridge inside the machine.
Related Reading: How to Add Toner to a Canon X25
Step 3
Grab the handle at the top of the current toner cartridge and lift the cartridge upward. Pull the toner out of the machine and set it aside.
Step 4
Set your replacement toner cartridge over the empty space in the fax/copy machine. Ensure that the arrow near the bottom of the cartridge is facing down, and line up the protruding guide piece on the left side of the cartridge with the groove inside the machine. Push the toner downward until it snaps into position.
Step 5
Push the paper delivery tray back down, and lift up the extension piece if your model uses one.

To adjust the default lighter/darker setting

1. On the LaserJet 3015, press MENU/ENTER.

2. Use the < or the > button to select Copy setup, and then press MENU/ENTER.

3. Use the < or the > button to select Def. Light/Dark, and then press MENU/ENTER.

4. Use the < or the > button to adjust the setting. Move the slider to the left to make all of the

copies lighter than the original, or move the slider to the right to make all of the copies

darker than the original.
5. Press MENU/ENTER to save the selection.

Page 48 of the User Guide has instructions for adjusting the light/dark setting during a copy job.

Also see the Troubleshooting section of the User Guide for other possible reasons for light/faded copies.

If your copies continue to come out too light, you may need to clean the insert a new toner cartridge or change brands of toner. I tried several "generic" toner cartridges and refills, but my prints and copies were always faded or streaky. After going back to genuine HP cartridges, I haven't had any print quality problems.

are u using a compatible toner or branded.this problem might be occurring due to toner .try to change the toner and developer .both at the same time because if u change the toner then the toner in developer module will get mixed with new one and u will have a problem

try testing with the old cartridge if possible. If not i still would replace the cartridge. any time a problem arises after a cartridge replacement it is normally the cartridge

Defective toner cartridge. Try sliding out the cartridge, turn it over and slide open the cover/gate that covers the drum. The drum should be clean all the way across. If you see a toner band or anything that would be your proof. 9 times out of 10 this is going to be a bad toner cartridge.

The drum, developer and other parts have a certain life that they are good for. After they go beyond that cycle they can start to run dirty, use alot more toner, basically give you problems until a complete maintenance is done. The drum can have permanent light fatigue, even though they look good and in alot of cases one side will start to get darker than the other. You should get an estimate of what it'll cost to have servicing done and compare that with the cost of a new or refurbed machine. If the copier is very old, it might be worth it to get a new one. Good luck, please rate this if it helped you. Thanks

transfer belt worned out.

Hello,
You can try a couple of things,
1. Verify that the pull strip was removed from the toner cartridge before it was supposed to be installed.
2. Shake the toner cartridge side to side to loosen the toner inside.
3. Clean the inside of the printer with a can of compressed air.

Good Luck!
Rich Lilja

sounds like the toner cartridge is failing, try another one

check the toner cartridge if thats not the problem you may need the fuser replaced