Service mode on 7900

[PeterAit]

I have watched a video explaining how to take out the wiper blade for cleaning, but I cannot get into service mode. The video I watched says that, with the printer off, hold down the right arrow, down arrow, and OK buttons at the same time, then press the power button. I have tried this several times but the printer always boots up into normal mode. What am I missing?

[Paul2660]

When you hold down the buttons, make sure you keep them down until you see the LCD light up with a series of boxes for the ink carts.  They should show empty at first.  If you let go too soon, then the printer boots up normal. 

If you have Down arrow, OK, and Right arrow all pressed at the same time and wait till you see the LCD display the boxes, you will come up into Service mode.  It take a few seconds after power up.

Paul