HP 750 - Manual (Page 173)

Troubleshooting C4705-90000 8-55
Troubleshooting Tips
Repair and calibrate. After you have made a repair, consider whether any calibrations
have been affected.
Cartridges fail
frequently.
Remove tape and align cartridges: One frequent cause of
cartridge problems is that the user has forgotten to remove the tape
from new cartridges. Remove the tape.
Damaged encoder strip: Another frequent cause of apparent
cartridge failure may be a damaged encoder strip. If the small slots
on the strip are damaged, the plotter cannot position the carriage
correctly during cartridge checking. Try replacing the encoder strip.
Worn wipers: If the wipers in the service station are worn down,
they do not properly wipe the cartridge heads. Easy to replace.
Carriage sensor does
not correctly find
media edge.
Ink on roller: Excessive ink deposits on the driveĆroller surface
can fool the sensor by reflecting the light. (Cleaning roller '
chapter 4.)
Optical sensor incorrectly calibrated: The accuracy calibration
includes calibration of the optical sensor on the carriage. You must
use polyester film when performing the accuracy calibration.
Otherwise the optical sensor will have problems loading some types
of media.
Drive belts wear out
prematurely.
Diazo copiers: The belt may wear prematurely if the plotter is
placed near a diazo copier that uses ammonia to produce blueĆline
copies. The material used in the belt is very reactive to ammonia
vapor. The vapor is very corrosive and can damage other parts as
well. Move the plotters away from such copiers.
Storing: Keep new belts in their bags with dissicant until you need
to install them. This is to avoid incorrect swelling.
Noisy carriage
movement.
Dirty carriage bushing: Remove aluminum or dust particles
from the bushing at the back of the carriage, and from the slider
path along which the bushing moves.
Ink spilling. Spittoon and ink separator: You need to replace these parts
when they fill up with ink. (See ' chapter 4.)
ThirdĆparty ink and
offĆaxis ink systems.
Drawer statement: HP does not support thirdĆparty inks or
offĆaxis ink systems for use withany of its DesignJet series plotters
or printers. If a failure or damage to suchHP products is found to
be directly attributed to the use of thirdĆparty inks or offĆaxis ink
systems (or any other nonĆsupported HP supply or accessory), the
repair will NOT be covered under HP's warranty or maintenance
contract. In suchcases, standard time and material charges will be
applied to service the plotter or printer."
Troublesome
plotters.
Duty cycle: Plotters need increased maintenance if users do not
limit use to the dutyĆcycle recommendations. (Details ' chapter 4.)