HP designjet l65500 Manuale Di Servizio

 Troubleshooting

235

The colored crosses on the left side of the plot should show the lines well aligned with each other.

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The central die of the light cyan printhead is used as a reference to which the rest of the pens are 

compared. The substrate does not move while the pattern is printed.

The vertical lines to left of center should be straight, without kinks.

The small arrow points to the place where lines printed in subsequent passes meet. The registration 

should be checked at that point for the KC, lm and MY printheads (MY is not shown). Please note 

that media advances between the printing of the upper and lower parts of the plot.
The Angular alignment check is heavily dependant on perturbations of the substrate. Occasionally, 

events such as IPS Substrate Load or any other that repeatedly moves substrate forward and 

backward may distortion the Angular check. In this case, move media forward for 20 inches and 

repeat the Printheads Alignment Diagnostic plot.
Problems in the Angular alignment lead to M-Y to C-K pen-to-pen mis-registration. This is because of 

the staggered disposition of the Printheads. For example, if an M line has an incorrect Angular 

alignment it will move towards Media Output with a certain skew, and a subsequent K line in the 

same position will show misregistration.
The Angular alignment can slightly change when media type or size varies, or when media has 

recently been loaded into the printer.

Pattern printed before media advance

Pattern printed after media advance