HP 16V - Manual (Page 133)

Warning Messages
Warning
Messages
This printer counts the number of the printed sheets to estimate the
life of the consumables (print unit). The printer indicates the
following warning message when and after the count reaches a
predetermined value.
READY
REPLACE PARTS
When the warning message is indicated, press the button to
put the printer offline and press the button to enter menu
mode. The Clear Warning message appears, indicating the expired
unit by an asterisk. When the print unit is expired, the message is:
<CLEAR WARNING>
PRINT UNIT*
However, depending on the print quality, you may not have to
replace print unit because you may suit be satisfied with the print
quality.
5-18 User’s Manual