HP Designjet Z3100 Photo Printer series - Manual (Page 150)

And here is an example of the same printhead in a bad state:
The gloss enhancer (E) cannot be seen when printed on its own, because it is a clear fluid. To make it
visible in the Image Diagnostics Print, it is printed over gray ink (G).
● In part 1 (top), the gloss enhancer is seen as a slightly different gray inner section of a gray
rectangle. On some papers the inner section may look darker, on other papers it may look lighter.
● In part 2 (bottom), the small dashes of gloss enhancer, one for each nozzle of the printhead, are
seen as small lighter gray dashes on top of a gray area.
On most plain and coated papers the gloss enhancer can barely be seen, so such papers are not suitable
for troubleshooting the gloss enhancer.
Corrective action
1. Clean any faulty printheads (see Clean the printheads on page 145 ). Then reprint the Image
Diagnostics Print to see whether the problem has been solved.
2. If the problem remains, clean the printheads again, and reprint the Image Diagnostics Print to see
whether the problem has been solved.
3. If the problem remains, consider cleaning your printheads manually (see Clean the printheads
on page 145 ). You could also try reprinting your current print job, in case it now prints satisfactorily.
140 Chapter 12 Troubleshooting print-quality issues ENWW
Troubleshooting print-
qu
ality issu
es