Seems that after replace one toner it not be fully closed the lock so it's blocking the laser path to paper, reseat all toners and if it fail you should give info such as only fail with one color, only b&w...
also you could enter customer mode by keep pressing up and down arrows during power on, then go to test print and look down till 20% cyan(after magenta,after yellow and finally black) so you could print one page at 5% from each color and look wich fail
Which color is most impacted?
The best way to determine this is to print the 20% density test pages:
1. Power off the printer.
2. Press and hold the UP and DOWN arrow buttons while you power the printer on.
3. The buttons may be released after the LCD indicates "Diagnosing..."
4. After a few seconds, the LCD should indicate "Customer Mode" and "ESS Diag"
5. Press the UP or Down arrow buttons to find "Test Print", press the Enter (center) button.
6. Press the Down arrow button to find and select Cyan20%, or Magenta20%, or Yellow20%, or Black20%; press the Enter button twice to select and print that test page
(note: printers with the newest firmware may have an additional menu item called "ContaminationCHK". Using this item will print all 4 of the 20% density pages for you)
7. After all print tests have been completed, power the printer off, wait ~5 secs, and power on.
Lets assume for a moment that your 20% BLACK page has the problem, and no other colors.
This is gonna sound weird, but use the front panel to replace the Yellow toner, remove and re-seat the Yellow toner cartridge. Ensure the rotating toner lock handle is completely rotated all the down into the locked position. This is very important.
The reason this happened is because as the carousel (the big thing in the center of the printer that holds the toner carts) rotates, each time it stops to transfer a color, the toner cart of the "next color" in sequence is very close to the laser beam path, in this case Yellow. If the locking handle on that cart is protruding at all, it will block the laser beam and the result wil be a huge blank area down the side of the page.
As you view the carousel from the front where you replace the carts, rotation of the carousel is downward.
Yellow can effect Black (as per this example)
Magenta effects Yellow
Cyan efects Magenta
Black effects Cyan
Hi, I did all this but the test pages would not print. And now when I power off the printer and power on after 5 sec the printer just go back to Diagnosing menu. Can't go to normal mode. Please help.