Print Image size problem

Hello,

I have brought a second hand xerox phaser 3117 for hobby project (for creating pcb mostly). but i am having a problem with my print image size e.g when printing DisplayBoard.png different portion page yield different print size, if i print it in OHP paper
and overlapped the image all four image are of different size.

Does any body have a solution what the problem might?? i need to get this right as this will be my primary usage.

I have opened it for serving and cleaning and found...

Print Image size problem