HP designjet l65500 Manuale Di Servizio

242

Troubleshooting

The Bidirectional Alignment along Scan Axis plot shows the error committed during bidirectional printing 

(printing in both directions). This error is revealed by means of an interference or vernier pattern that spans 

the whole Scan Axis of the printer. In fact, for technical reasons the plot is limited to 70‚ (or to the media 

width, whichever is smaller).

Bidirectional alignment diagnostics

Each thin band corresponds to one Falcon die. That is why there are 5 bands per color. The white 

wavy strip in the middle of each band indicates the error in the bidirectional alignment. The waves 

seen correspond to the platen ribs and are normal. If printheads are aligned, the white strip should 

be vertically centered within its band.

PRS diagnostics (Pen to Ribs Space [platen ribs])

For PRS diagnosis only the black portion of the plot will be used. Choose one of the 5 black bands 

(the one that has less nozzle outs or that looks better in general). The objective is to see if the white 

stripe remains centered in the band along the scan axis. Any PRS variation shows up as a deviation 

of the white strip up or down its band.

To find the value for D, use the following procedure.

1.

Choose the band that exhibits the most variation for the black color.

The higher the position of the strip on the plot, the higher is the PRS.

In most cases the PRS values at the plot extremes are higher than in the center.