I have canon LBP2900B printer. there is problem when i print paper it outcomes black left and right sides. please help me

I suspect you have had a paper jam and removed the paper. However some still remains inside the machine. Its most probably around the purge unit. When the carriage parks on the right side of the machine, the purge unit rises to cap the carriage so your print head does not dry out. Open the internal cover so you can see the carriage. If it is anywhere other than at the far right side of its travel then kill the power by unplugging from the mains supply. Now the carriage is free to push. push it all the way to the left side. Shine a torch into the printer and you will see the purge unit on the right side. It has two black oblongs of rubber that mate with the print head. There will be paper scraps around it.Or it may be stuck and with a long screwdriver you can push it gently backwards to free it. If none of this helps and the carriage is stuck on the right side then again kill the power and rotate the long black roller that is under the carriage. Do this while gently trying to push the carriage to the left until its free to move then follow the above again.

The printer is only able to print on one side of the page at once.

In order to print on both sides you will need to print only 1 page. This is set on the left side window that comes up before you print. Select the option to print Page number 1.

Then once the page is printed, turn it typed side down heading first, back into the paper tray.

Now select to print Page number 2.

This process is called manual duplex printing, since the printer does not support automatic duplex printing.

Take care!
damnor01

Problem may be in Tonner or Fuser slib
Fuser slib may be damaged replace it if damaged

you can easy replace your printer cartridge and see what will happened. Probably there is a problem with the drum of your cartridge. Also maybe the waste toner section is full. First cleaned it!

you will need the Duplex Unit installed for double sided printing

Clean your Rubber Spooler inside the Printer which had become dirty .
Possiblity of Damaged Catridge

how to print 300 dpi in Canon LBP2900B Laser printer

Try running its Clean Cartridges command.

you have to clean the developer speciali if they are straight lines...also see if it has wheels on the sides they are probably covered with tonner

press resume button at least 4 seconds