HP V8.5 - Manual (Page 66)

T R O U B L E S H O O T I N G
7
7-6 V8.5e Rev 2.2.2002
Plot has black vertical lines
Figure 7-6 . Plot with black vertical lines
Possible Cause: One or more bits in each byte going to the
plotter are “stuck high”.
Solution:
1. If your plotted output from the host shows these lines, run a test
plot. If the lines are not present on the test plot, the problem
originates with the host data. Check the interface data cable from
the host and replace it if neccesary.