90:03 or 89:03 Error on Designjet T920/930/1500/2500

"This is one of the ramps (diverter valves) as seen from behind the machine when the stacker is attached. You must remove the stacker in order to lower the ramps."

If you're getting this error, you more than likely had the stacker off your HP Designjet T920, T930, T1500, or T2500.

It would be nice if the manual was a little more clear on what the problem is.  all it says is, "90:03 Diverter valves motor error".  If you try to search for "diverter valves," you still end up confused, because "valves" isn't really explained.  Here's a hint, "valves" in the newest HP talk refers to what you might think of as "ramps" or "paper guides."

There's no valve.  They're referring to the pieces of plastic that guide the paper either into the stacker or down below into the paper catcher.

In the directions to remove the stacker, you see this little nugget down at the bottom:

"NOTE: For installation make sure that the valves are down and the ramps are hidden, otherwise it can cause improper assembly, and show SE90:03 or SE89:03."

But there's no clear way of finding out what they're talking about.  In fact, if you're like me, you just have to go ahead and make the mistake before figuring it out. Which I did.

If you take the stacker off, and look down at the exit rollers that are visible, you'll see a set of plastic ramps (valves).  You can move them up and down by manipulating the diverter valves motor.  It is refered to simply as the "valves motor" in the removal instructions.  So you can use the manual to remove it and free up the gears (enabling you to move the ramps) or you can just turn the motor as shown in the video below.

But remember: you can't move them if the stacker is attached.  So unattach the stacker and then rotate the motor to make sure the ramps are moving up and down freely.  Then make sure the ramps are all the way down, reattach the stacker and the valves motor, and you should be good.