Loveshaw MicroJet I User manual

Little David® Technician's Manual
MicroJet I™
MicroJet I Plus™
MicroJet II™
MicroJet III™
MicroJet III HC™
INK JET CODER
by
Trouble-Shooting Guide
PART NUMBER: CPM200-TSG

Loveshaw, an ITW Company
2206 Easton Turnpike, PO. Box 83
South Canaan, PA 18459
Tel: [phone]
Fax: [phone]
www.Loveshaw.com
[email protected]
Loveshaw Europe A Division of ITW LTD.
Unit 9 Brunel Gate
West Portway Industrial Estate
Andover, Hampshire SP10 3SL
ENGLAND
Tel: [phone]
Fax: [phone]
[email protected]
Document revised September 2004. Copyright © 2003, 2004 Loveshaw, an ITW Company All rights reserved
worldwide.

Table of Contents
MICROJET Trouble-Shooting Guide iii
ntroduction ............................................................................................................. 1I
) Ink lamp stays on ............................................................................................... 2
A
) Ink lamp does not come on when ink container is empty.................................. 2
B
) Unit does not purge ............................................................................................ 3
C
) Heavy printing.................................................................................................... 3
D
) Weak print/output............................................................................................... 4
E
) Printing starts heavy and weakens when printing long messages ...................... 4
F
) Photocell LED(s) does not light......................................................................... 4
G
) Photocell LED(s) does not turn off.................................................................... 4
H
) Display does not come up.................................................................................... 5
I
) CPU losing date/time when unit is off ................................................................ 5
J
) Valve does not print but purges ......................................................................... 5
K
) Valves print but will not purge........................................................................... 5
L
) Pump does not run............................................................................................. 6
M
) Ink leaks from ink bottle cap ............................................................................. 6
N
) Product delay/character width changing on product.......................................... 6
O
) Ink not drying on product ................................................................................... 7
P
) Nozzle plate weeps ink ...................................................................................... 7
Q
) Nozzle blocked................................................................................................... 7
R
) Tubing loose on valve ports................................................................................ 8
S
) Unit locks up after installation ........................................................................... 8
T
) Tailing output..................................................................................................... 8
U
ow ink lamp/reservoir lead removal ...................................................................... 9
L
ir pump pressure adjustment................................................................................ 10
A
iagrams ................................................................................................................ 12
D
attery Replacement .............................................................................................. 25
B
ill of Materials / Quick Reference Chart ............................................................. 26
B
Warranty................................................................................................................. 28

MICROJET Trouble-Shooting Guide 1
Introduction
Head:
This document covers hardware procedures for the
Loveshaw MicroJet Printers which include MicroJet I,
MicroJet I Plus, MicroJet II, MicroJet III, and MicroJet
III HC. Procedures are described in a simple list form
keyed to hardware fault, so that technicians can quickly
diagnose and fix such problems.
( Personnal Protection Equipment such as safety
glasses and other protective gear should be worn
when servicing ink jet printers.)
NOTE: Refer to attached assembly drawings when troubleshooting. Further
assistance can be obtained by calling your local distributor or Loveshaw
factory service technician at 1-800-962-2633.
Head:

MICROJET Trouble-Shooting Guide 2
A) Ink lamp stays on
* New units shipped from the factory contain a solution that will cause the
lamp to remain on. This solution must be completely purged out, and ink
purged through, before the lamp will go out.
* Purge unit, light should go out.
* If lamp remains on, remove the two screw on the front cover.
* With power disconnected, look for broken wire at reservoir.
* If lamp remains on, remove tie wrap which hold wires to Power Supply
Board and lower the wire harness.
* Test resistance across pins 1 and 2 on side “A” of four pin connector.
Resistance across reservoir pins should measure approx. 1.5 meg. ohm (See
Troubleshooting Chart at end of this list.)
* If lamp remains on, call for service.
Head:
B) Ink lamp does not come on when ink container
is empty
* If lamp remains on, remove tie wrap which hold wires to Power Supply
Board and lower the wire harness.
* Test resistance across pins 1 and 2 on side “A” of four pin connector.
Resistance across reservoir pins should measure approx. 1.5 meg. ohm (See
Troubleshooting Chart at end of this list.)
Circuit should be open.
* Check resistance of lamp between pins 3 and 4 on four pin connector on
side “A”. Resistance should be 25 ohms. If circuit is open replace lamp. See
LOW INK LAMP/RESERVOIR LEAD REMOVAL procedure.
* Check voltage between pins 1 and 2 on four pin connector on side “B”. A
very small voltage of .075 volts DC should be present. If no voltage is
present, replace CPU assembly.
* Check voltage between pins 3 and 4 on four pin connector on side “B”.
Voltage should be 25 volts DC. If no voltage is present, replace CPU
assembly. (See Quick Reference Chart for part numbers.)
* If lamp remains out, call for service.
Head:

C) Unit does not purge
* Test pump pressure. Pressure should be between 2.0 and 3.0 psi. If
pressure is zero, proceed to step “M”.
* Check ink level in container and replace if empty.
* Check for kinks in tubing and replace, if necessary.
* Test for ink flow from brass cap/ink container: Crimp tubing going into
reservoir from ink container. Remove tubing from inlet of reservoir and test
for ink flow by loosening crimp (discharge into container and avoid getting
ink on circuit cards). If no flow is present, replace ink container and/or brass
cap.
* Test for ink flow from reservoir. Crimp tubing going into reservoir from
ink container. Remove tubing from inlet side of filter. Carefully loosen
crimp and test for ink flow (discharge into container and avoid getting ink on
circuit cards). If a weak ink flow or no flow is present, replace reservoir. See
LOW INK LAMP/RESERVOIR LEAD REMOVAL procedure.
* Test for ink flow from filter: Crimp tubing going into reservoir from ink
container. Remove tubing from inlet side or off-center port of valve.
Carefully loosen crimp and test for flow (discharge into container and avoid
getting ink on circuit cards). If a weak flow or no flow is present replace
filter.
Head:
D) Heavy printing
* Check dot size setting (<SIZE> key). Lower if needed.
* Check incoming voltage from transformer. Voltage between pins 1 and 2
on transformer connector should be approximately 20 volts AC (See
Troubleshooting Chart at end of this list.)
* Purge to remove air.
* Check individual valve adjustment (<MENU> then 8). Lower if needed.
* Test pump pressure (2.0_3.0 psi) if higher, adjust. See AIR PUMP
PRESSURE ADJUSTMENT procedure.
Head:
MICROJET Trouble-Shooting Guide 3

E) Weak print/output
* Check dot size; increase as needed.
* Check purge output; all nozzles to give a 2 inch stream of ink or greater.
* If weak printing continues, go to letter “C” testing ink flow.
Head:
F) Printing starts heavy and weakens when
printing long messages
* Purge for air removal.
* Check purge, which should be steady; if not, go to letter “C” testing.
Head:
G) Photocell LED(s) does not light
* Test photocell by placing a white piece of paper directly in front of unit;
LED(s) should come on. If not, turn photocell holder(s) gently from side to
side and note if LED light(s) come on; leave in position that lights LED(s);
slowly pull paper back from unit and note distance at which LED goes out;
should be 2 inches or more. If not, replace photocell . (See Quick Reference
Chart for part numbers.)
Head:
H) Photocell LED(s) does not turn off
* Check that there is no reflective material in front of unit. If so, the material
should be painted a “flat black” color (infrared does not reflect well off of a
flat black surface.)
* Turn photocell holder(s) gently from side to side and note if LED light
goes out.
* Power the unit off then on; LED light should be off, if not, look for ink or
water on board(s) or unit.
* If ink or water is on boards remove and flush/dry overnight. Retest next
day.
* LED light is on, and will not go out, replace CPU board (See Quick
Reference Chart for part numbers.)
Head:
MICROJET Trouble-Shooting Guide 4

I) Display does not come up
* Check if pump is running; if not, check that transformer is operating
properly. (See Troubleshooting Chart at end of this list.)
* If pump is running, check AC fuse under front cover and replace if blown.
* If fuse continues to blow, replace power supply board. (See Quick
Reference Chart for part numbers.)
* If fuse does not blow, test voltage at power board. If proper voltage is
present replace CPU.
* If proper voltage is not present, call for service.
Head:
J) CPU losing date/time when unit is off
* Reset and monitor for 24 hours with unit off.
* If retest fails, CPU battery must be replaced. See battery replacement
procedure.
* If CPU looses date/time with unit on, replace CPU.
Head:
K) Valve does not print but purges
* Plug a working valve in that position and test. If printing occurs, replace
valve. If no printing occurs, check ribbon cables, replace Valve, CPU or
Driver Board.
L) Valves print but will not purge
* Test continuity of purge switch with unit off and purge switch depressed.
Replace if defective; should be zero ohms.
* Test valve board resistor/diode for proper values (See Troubleshooting
Chart at end of this list.)
MICROJET Trouble-Shooting Guide 5

M) Pump does not run
* Remove transformer power cord from unit and check for proper AC
voltage at connector. (See Troubleshooting Chart at end of this list.)
Replace transformer if defective.
* Remove front cover and check electrical connectors on pump. If proper
voltage is present at pump and pump is not running, remove wires (2) going
to pump, and check resistance across pump coil (See Troubleshooting Chart
at end of this list.)
* If no voltage is present at pump connectors check transformer and AC
outlet.
N) Ink leaks from ink bottle cap
* Remove brass connector and check for presence of “O” rings on the under
side of brass connector and replace if missing or damaged.
* Tighten container cap.
* Reposition container and check for leaks.
* If leak continues, replace bottle with a new one and retest.
* If leak continues, replace ink bottle cap assembly.
O) Product delay/character width changing on
product
* Check the orientation of box to MICROJET — it must be perpendicular.
* Clean photocell filters with water, and check that both photocell LED
lights come on when product passes by. If photocell LED does not come on,
go to procedure “G”.
* Check to insure no extraneous spaces are inserted before or after text in
message. If so, delete extra spaces.
* If problem continues, check for dark colored bands on box. (Photocells
will not detect black). Test with a blank box.
* If product delay/character width continues to move, call for service.
MICROJET Trouble-Shooting Guide 6

P) Ink not drying on product
* Check dot size setting ( <SIZE> key); lower if needed.
* Check pump pressure should be between 2.0 and 3.0 psi. If pump pressure
is out of adjustment, see AIR PUMP PRESSURE ADJUSTMENT
procedure.
* Check to be sure box is not waxy or oily (make sure substrate surface has
not changed).
Q) Nozzle plate weeps ink
* Wipe nozzle plate with a damp paper towel and check to see if ink forms
on nozzle plate.
* If ink does not form on nozzle plate, print 5-10 boxes and check. If ink
forms, replace nozzle plate tubing.
* Remove valve at location generating weeping.
* Connect valve to a 9 volt battery and flush water into outlet post with a
syringe and a piece of .040 tubing.
* Replace valve and retest.
* Connect tubing to outlet of valve from the nozzle plate and purge
* Repeat backflush and purge if necessary
* If weeping persists, replace valve.
R) Nozzle blocked
* Remove tubing from center port of valve that supplies fluid to blocked
nozzle.
* Connect drain hose (from maintenance kit) to tubing attached to back of
nozzle plate.
* Place other end of drain tubing outside of unit and drain into a container.
* Place tubing end of syringe with cleaner, over orifice that is blocked and
apply pressure (you will see fluid move down drain tube).
* Continue flushing until tubing is clear of ink.
* Disconnect syringe and reconnect tubing to valve port.
* Purge and retest.
* Repeat if necessary.
* If nozzle is still blocked, replace the nozzle plate assembly.
Head:
MICROJET Trouble-Shooting Guide 7
S) Tubing loose on valve ports

* If tubing is brittle, replace with new .050 X .070 tubing (p/n
CPJ00_024_0).
* If tubing is not hard, remove the valve (clamp off all pressure lines first)
and cut off 1/8 inch from ends and reposition on valve.
* Note: Both valve port and tubing end must be dry to ensure a tight fit. Dry
tubing end by rolling the corner end of a paper towel into a fine point and
insert into tubing end.
T) Unit locks up after installation
* Connect transformer to a Power Backup Supply UPS (available from
Loveshaw).
* Supply a dedicated line plus use regulated supply.
* Insure A.C. outlet has a proper ground.
* Make sure the conveyor line is properly grounded to a low impedance
ground (less then 5 ohms).
* If you are unable to unlock the MICROJET by turning it on and off, do
the 666 SLAM function (see operators manual for additional information on
666 SLAM procedure).
U) Tailing output
* Check distance between head and substrate; should be 1/2 inch max.
* Check dot size setting, readjust global and individual.
* Make sure unit is level and not being subject to excessive vibration.
* Purge system of air with lid at approximately 45 degrees.
* Check pump pressure (see AIR PUMP PRESSURE ADJUSTMENT
procedure).
* Check tubing lengths going from valve to nozzle plate (see nozzle plate
drawing).
* Backflush nozzles as needed.
* Change nozzle plate.
* Increase character width and check line speed.
MICROJET Trouble-Shooting Guide 8

Low ink lamp/reservoir lead removal
To remove either low ink lamp leads or reservoir leads from the four-pin
connector, follow steps as listed:
* Turn unit off.
* Open lid.
* Remove ink bottle; place cap on bottle and set aside
* Remove two screws from pump cover, one on each edge, and set aside.
Next to the 2 amp fuse is two
Tie Wraps which hold the
cable harness in place. They
must be cut to loosen this
harness so that measurement
and rework can be done.
* Disconnect four pin connector from modular board to lamp/reservoir leads
by pulling male and female of connector apart.
* If a pin extraction tool is not available, use a fine point object with safety
gloves, to push two locks of male pins inward towards pin body.
* As locks of pin are being folded in, firmly tug wire away from connector.
* Repeat for each pin removed.
* Firmly tug wire away from connector.
* Repeat for each pin removed.
Head:
MICROJET Trouble-Shooting Guide 9

MICROJET Trouble-Shooting Guide 10
Air pump pressure adjustment
* Turn unit off.
* Open front cover.
* Remove ink bottle; place cap on bottle and set aside.
* Turn the brass knob clockwise for higher presser or counter clockwise for
lower presser.
* Verify pump pressure at air port of brass bottle cap using gauge assembly
and turn the unit on.
* Repeat procedure to obtain desired pump pressure.

Copyright Loveshaw 2003, All Rights Reserved.
Copyright Loveshaw 2003, All Rights Reserved.
MICROJET Trouble-Shooting Guide 11

Copyright Loveshaw 2003, All Rights Reserved.
MICROJET Trouble-Shooting Guide 12

Copyright Loveshaw 2003, All Rights Reserved.
MICROJET Trouble-Shooting Guide 13

TROUBLESHOOTING CHART
CHECKING AIR PUMP COIL ASSEMBLY CPM75-208-B
SET METER TO V~ AND
TAKE READING ON
TWO TEMINAL
CONNECT TO POWER.
IT SHOULD BE 19.5
VAC. POWER SHOULD
BE ON.
SET METER TO OHMS
AND TAKE READING
ON DISCONNECTED
TERMINALS WITH
POWER OFF UNIT.
IT SHOULD BE 32
OHMS.
LOW INK LIGHT CONNECTOR CHECK
SET METER TO DC VOLTAGE.
NOTE :
TWO TOP WIRE ARE FROM RESERVOIR AND
BOTTOM TWO ARE FROM THE LAMP.
POWER MUST BE ON.
POWER SUPPLY TRANSFORMER CHECK
CPM11-003-120 CPM75-003-115
CPM11-003-240 CPM75-003-240
SET METER TO AC VOTAGE.
MEASURE THE TRANSFORMER
PLUGED INTO AN AC OUTLET.
PIN #1 + POSITIVE
PIN #2 – NEGATIVE RETURN
PIN #3 GROUND
PIN #4 NO CONNECTION
LOW INK LIGHT CONNECTOR
DIODE RESISTOR
CPJ00-009-0 & 25 OHM
SET METER
TO OHMS
MICROJET Trouble-Shooting Guide 14

Copyright Loveshaw 2003, All Rights Reserved.
MICROJET Trouble-Shooting Guide 15

Copyright Loveshaw 2003, All Rights Reserved.
MICROJET Trouble-Shooting Guide 16

Copyright Loveshaw 2003, All Rights Reserved.
MICROJET Trouble-Shooting Guide 17