Oki ML-520 printer. When printing it will progressively move the print across the page from left to right, a few characters at a time

You would have to cancel the current print job from your computer for it to stop. Assuming you have access to a computer that is connected to that printer, you will have to find that printer by going to Control Panel > Printers and Faxes > Oki ML 320 then right click, select "See What's Printing" and cancel Current print job (I am also assuming you are using windows). I really hope this helps, if not add a comment clarifying your question, thanks.

Go to Start / printers and faxes / Right click on print icon / properties / print test page.

Here is a web page with many drivers to choose fromm

http://www.google.com/search?q=OKI+MICROLINE+520+Matrix+Printer+NEED+A+PRINTER+DRIVER+FOR+THE+ML+391+TURBO+&rls=com.microsoft:en-us:IE-ContextMenu&ie=UTF-8&oe=UTF-8&sourceid=ie7&rlz=1I7ADFA_en

need to go into printer config and configure the characters per line.

Kindly check the DPI settings . May be more DPI this time.

Best Regards
Rafique

Yes quite possible pin broke on head, check ribbon is fitted correctly and has plastic sheild on front of it intact

What driver are you using for this printer? Try loading a Epson LQ1050 driver and try again.
Dezzi

Try printing the menu like this -With power on press the "Shift" tand "Select" button, a red menu light will pop up on the touch panel ! than press the "Print" button on the touch panel-this will print out the current settings of your printer.
Good luck
Dezzi

check the printer drvier properties and make sur the defaulf is not set to print 2 copies.

I assume you've checked Page setup in the particular software you are using. It seems unlikely, but perhaps something is awry with the printhead home position sensor. This device is on the left side of the printer, and essentially sets a reference point, and the printing start position is counted from this reference. Sometimes this sensor is an optical device, other times a mechanical switch. The latter would be more apt to cause problems. If another tech has a better solution, say on!