HP 7470A Operator's Manual page 33

Possible Cause
Plotting Does Not Occur Where Expected (Continued)
Program has
Fiber-tip pen is dried out.
The pen is defective.
Fiber-tip pens have been
stored longer than their speci-
fied shelf life.
28
error.
an
Pen Does Not Write
Pen Dries Out before It Is Used
Solution
Lines may not be drawn
where expected due to a pro-
gramming error. Check the
program listing.
Prime the pen by manually
writing with it until the ink
begins flowing from the inter-
nal ink supply to the pen tip.
If very dry, dip the tip in a
drop of water or ink solvent to
initiate ink flow, or shake it
like a thermometer.
Keep the caps on fiber-tip pens
whenever they are not stored
in the pen stall. Leave new
pens in their hermetically
sealed foil packages until they
are needed.
Although rarely the case, it is
possible that a pen is defective
and will not write from the
beginning. Check all other
possibilities first.
Fiber-tip pens are packaged in
hermetically sealed foil enve-
lopes that preserve the pens.
in
New pens that have been
stored an unopened package
are guaranteed to write if used
by the date stamped on the en-
velope. Order carefully to
avoid having the shelf life ex-
pire before pens are needed.
Always leave packages sealed
until the enclosed pens are to
be used.