Welch Allyn LS-135 User manual

Welch Allyn Medical Division
LS 135/150 Examination Light
Service Manual
4341 State Street Road
P.O. Box 220
Skaneateles Falls, NY 13153-0220
443194 Rev. B Copyright 2002

Welch Allyn Exam Light i
LS 135/LS 150 Service Manual 443194 Rev. B
Drawings and/or illustrations and/or part numbers contained in this document
are for reference purposes only. For current revisions call the Welch Allyn
Customer Service phone number listed in Section 1 page 3.
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ii Welch Allyn Exam Light LS 135/LS 150 Service Manual 443194 Rev. B
Contents
Section 1: General Information
About the LS 135................................................................................................................................1
About the LS 150 ...............................................................................................................................1
Approvals ............................................................................................................................ 1
Safety Warnings. .................................................................................................................. 2
Help Information................................................................................................................................3
Section 2: Service
Incoming Inspection/Checklist ........................................................................................... 1
Required Tools .................................................................................................................... 1
Section 3: Troubleshooting
Mechanical checks .............................................................................................................. 1
Electrical checks.................................................................................................................................2
Section 4: Repair and Disassembly
LS 135 Floor Model Dissambly ........................................................................................... 1
LS 135 Wall Model Dissambly.........................................................................................................9
LS 150 Wall Model Dissambly .......................................................................................... 14
LS 150 Floor Model Dissambly.....................................................................................................17
Appendix A: Repair Parts Lists
Appendix B: Exploded View Photo Illustrations
Appendix C: Electrical Schematic

General Information Section 1
LS 135/150 Service Manual 443194 Rev. B Welch Allyn Exam Light 1
About the LS 135 Examination Light
The LS 135 examination light is a 35-watt halogen light that produces significantly whiter, brighter light than
the ordinary gooseneck units. The dual intensity control switch allows you to instantly adjust light output to
meet your exact requirements. Amolded lexan light head does not conduct heat, keeping the luminaire cool
to the touch. Multiple installation options include floor stand, table mount, wall mount and caster base.
About the LS 150 Examination Light
The LS 150 features a color corrected 50 watt lamp that delivers superior light quality across the
variable spectrum for more accurate color rendition. The special designed light head keeps the luminaire
cool to the touch even during multiple exams. The lamp has been offset at a 12 degree angle relative to the
luminaire housing, allowing an unobstructed view of the field of interest.
Approvals
CUS
ETL listed
UL2601-1,
CSA C22.2 No. 601.1
IEC 60601-1, AS 3200.1
IEC 60601-1-2
The CE mark on this product indicates that it
has been tested to and conforms with the
within the 89/336/ECC
Electromagnetic Compatibility Directive.
provisions noted
N344
Australia EMC Framework Compliance

Section 1 General Information
2 Welch Allyn Exam Light LS 135/150 Service Manual 443194 Rev. B
Cautions and Warnings
INTENSE LIGHT: Lamp is extremely bright. Do not stare at the lamp
when in use. May be harmful to eyes.
CAUTION: Remove power cord from electrical outlet and allow
lamp to cool 10 minutes before replacing with Welch Allyn lamp.
DANGER: Electric Shock Hazard. Refer servicing to qualified
service personnel.
DANGER: Risk of explosion if used in the presence of flammable
anesthetics.
HOT SURFACE: Lamp surface is hot. May be harmful to skin if
touched.
NOTE: This product complies with current required standards for electromagnetic
interference and should not interfere with other equipment or be affected by other
compliant devices. As a precaution, avoid using this device in close proximity to other
equipment.

General Information Section 1
LS 135/150 Service Manual 443194 Rev. B Welch Allyn Exam Light 3
Help Information
To assure correct operation and performance all service and repairs must be performed
by fully trained and properly equipped personnel, using genuine replacement parts and
correct procedures. Failure to do so will also invalidate the product warranty.
When calling, refer to the model number on the head of the Exam light.
Welch Allyn Inc.
State Street Plant /Corporate Headquarters
4341 State Street Road
Skaneateles Falls, NY 13153 0220, USA
tel: [phone]
315 685 4100
fax: [phone]
www.welchallyn.com/medical/support/tech
Welch Allyn Canada Ltd.
160 Matheson Blvd. E., Unit #2
Mississauga, Ontario Canada L4Z 1V4
tel: [phone]
905-890-0004
fax: [phone]
MD International
11300 N.W. 41st Street
Miami, FL 33178 USA
tel: [phone]
fax: [phone]
Welch Allyn GMBH
Zollerstrasse 2 4
72417 Jungingen, Germany
tel: [phone]
fax: [phone]
Welch Allyn France SARL
814 rue Charles de Gaulle
77100 Mareuil les Meaux
France
tel: [phone]
Fax: [phone]
Welch Allyn UK Ltd
St. Georges House
Vernon Gate, Derby
England DE1 1UQ
tel: [phone]-206208
fax: [phone]-206209
mob: [phone]
Welch Allyn Australia Pty
Metro Centre Unit 5
38-46 South Street
Rydalmere NSW 2116, Australia
Postal address:
PO Box 132
Rydalmere NSW 1701, Australia
tel: [phone]
fax: [phone]
Welch Allyn Singapore Ltd
300 Beach Road, #25-08
The Concourse
Singapore 199589, Singapore
tel: [phone]
fax: [phone]
China Service Center
Room 708, Central Plaza
No. 227 Huang Pi Bei Road
Huang Pu District
Shanghai 200003
China
tel: [phone]
fax: [phone]
Welch Allyn Japan K.K.
Bon Marusan 8F, 3-5-1 Kanda
Jinbo-Cho, Chiyoda-Ku
Tokyo 101-0051
Japan
tel: [phone]
fax: [phone]

BLANK PAGE

LS 135/LS 150 Service Manual 443194 Rev. B Welch Allyn Exam Light 1
Service Section 2
Incoming Inspection
NOTE: Use the following guidelines when unpacking the Exam Light from its shipping
carton.
1. Before opening the Exam Light shipping carton, check for damage.
2. If damage is apparent, stop unpacking the carton and contract the shipping company for
further instructions. If the carton is intact, unpack the Exam Light.
3. With the Exam Light out of its carton, check to see that all the items listed on the
packing slip are in the shipping carton.
4. If an item is missing, first check the carton, then check with your receiving
department. If necessary contact Welch Allyn at the Address and phone number
shown in Section 1 .
5. Clean and disinfect by following the instructions printed in the Operator Manual.
NOTE: Perform all functional tests before and after servicing.
6. Operate the Exam Light to verify the customer complaint before making any changes to
theunit. Call the customer if the complaint is unclear.
7. If the unit has caused or is suspected of having caused an injury of any type:
DO NOT DISASSEMBLE OR REPAIR THE UNIT IN ANY WAY.
Contact Welch Allyn Customer Service immediately.
Tools Required For Servicing Exam Light
Phillips Screw Driver
Standard Slip Joint Pliers
Needle Nose Pliers
Snap Ring Pliers
3/32 Hex Wrench
Pin removal tool
Digital MultiMeter

BLANK PAGE

LS 135/150 Service Manual 443194 Rev. B Welch Allyn Exam Light 1
Troubleshooting Section 3
Mechanical Checks:
1. Gooseneck - Replace if:
The shrink wrap is cracked/damaged or pulled back from either end.
The Gooseneck is damaged or kinked.
If it does not hold position - “droops” when checked in 4 directions.
2. Crush Rib Sleeve and Bushing: Replace if:
Damaged, cracked, or if o-rings are worn.
3. Head Rotation:
Position Head so it is parallel to the floor.
Rotate Head into several positions - it should hold in any position placed.
If it does not hold, replace the Bushing and o-rings on the Gooseneck.
4. If the reason for repair is due to rotation issues:
Turn on the unit & allow it to warm up 15 - 20 minutes, then check the rotation.
If it does not hold, replace the Bushing and o-rings on the Gooseneck.
5. Housings - Head or Base:
Replace any that have damage or cracks.
Check the Head housings for hairline cracks around the Bushing. Replace as needed.
6. Pole:
Replace any Poles that are bent.
7. Wire Harnesses/Connectors - Replace if:
Pinched, broken, or wire is exposed.
Electrical Checks:
The unit should NOT be plugged in at this time.
1. If Pole is not attached to the Base, check the wires at the both ends of the Pole, if wires
appear not damaged, assemble Pole into the Base.
2. Check for damaged or pinched wires at the connection between the Pole and Gooseneck.
3. Plug in unit (do not do this if any wires are damaged). Turn on unit.
Lamp works:
1. Turn Switch off and on several times. Light should not flicker while turned on. If you
are testing the LS 135 there should be an obvious change in light output between the
low & high settings. Switch should be consistent.

2 Welch Allyn Exam Light LS 135/150 Service Manual 443194 Rev. B
Section 3 Troubleshooting
Lamp does not work:
1. Turn off unit and unplug it. Check for blown or incorrect Lamp. Lamp should be 35W,
12V for the LS 135. Welch Allyn Part# 443069. Lamp should be 50 watt for the LS 150.
Welch Allyn Part# 445013.
2. Check connections between Pole and Gooseneck, the Base and Pole, and the Head and
theGooseneck.
3. If lamp still does not light then turn off unit.
4. Unplug it check the fuses located in the base.
5. If unit still does not light, perform Floor Model Switch Function Test.
Floor Model Switch Function Test (LS 135 Only)
Note: For this test, Unit should be unplugged from outlet! A known good Lamp should
be installed.
1. Disconnect Gooseneck Harness from Pole Harness.
2. Check for correct wire order: Pin 1 = Red, Pin 2 = Yellow, Pin 3 = White.
3. Set the meter to the lowest resistance setting.
4. Put one meter lead into the white wire pin and the other into the yellow wire pin.
5. Set the Switch on the Lamp Head to the low setting. The meter should read less than 1
ohm of resistance.
6. Set the Switch to the off position. The meter should read open.
7. Move meter lead from the yellow wire pin to the red wire pin.
8. Set the Switch on the Lamp Head to the high setting. The meter should read less than 1
ohm of resistance.
9. Set the Switch to the off position. The meter should read open.

Disassembly and Repair Section 4
LS 135/150 Service Manual 443194 Rev. B Welch Allyn Exam Light 1
NOTE: Disassembly of LS-135 Floor
model.
1. Loosen the screw that secures the
lamp nose assembly.
2. Lift lamp nose assembly.
3. Release the lamp retaining spring.
LS 135 Floor Model

Section 4 Disassembly and Repair
2 Welch Allyn Exam Light LS 135/150 Service Manual 443194 Rev. B
4. Unplug lamp.
5. Remove lamp head by removing 5
screws.
6. Remove lamp bottom housing.
LS 135 Floor Model

Disassembly and Repair Section 4
LS 135/150 Service Manual 443194 Rev. B Welch Allyn Exam Light 3
LS-135 Reassembly Note: Notice wire tie
and placement of wire behind standoff.
Reassembly Note:
NOTE: wire /switch connections and
placement of wire behind standoff.
white wire
red wire
yellow wire
brown lamp socket wires
7. To disassemble, disconnect wires and
remove gooseneck from lamp head.
8. Use small flat blade screwdriver to
pry the tabs of pole then pull
gooseneck bushing out.
Reassembly Note: Press the tabs back in
with a blunt object. A screwdriver
handle is shown below.
POLE
POLE
LS 135 Floor Model

Section 4 Disassembly and Repair
4 Welch Allyn Exam Light LS 135/150 Service Manual 443194 Rev. B
Note: Colors of wiring harness
on pole-end of gooseneck.
Red wire is in ‘key’ side of
connector.
9. Gooseneck assembly can be
disassembled as per the following steps.
10. Use pin removal tool to remove
connector block.
LS 135 Floor Model
RED
WHITE
YELLOW

Disassembly and Repair Section 4
LS 135/150 Service Manual 443194 Rev. B Welch Allyn Exam Light 5
11. Use 3/32” hex key to remove screw.
12. Pull bottom bushing away from
flexible arm.
Note the o-rings on lower flex bushing.
13. Remove snap ring from upper flex
bushing.
3/32” hex key
LS 135 Floor Model

Section 4 Disassembly and Repair
6 Welch Allyn Exam Light LS 135/150 Service Manual 443194 Rev. B
14. Remove upper bushing from flexible
arm.
Note: View of completely disassembled
gooseneck assembly and wire
harness.
15. To remove pole from base, remove
screw and bottom plate.
LS 135 Floor Model

Disassembly and Repair Section 4
LS 135/150 Service Manual 443194 Rev. B Welch Allyn Exam Light 7
16. Disconnect ground.
17. Disconnect harness.
18. Remove 5 screws from base.
Remove top cover.
LS 135 Floor Model

Section 4 Disassembly and Repair
8 Welch Allyn Exam Light LS 135/150 Service Manual 443194 Rev. B
NOTE: View of wiring and fuses:
(domestic LS-135 Pole Model)
Model: Application: Fuse Part #
44300 DOM #6 236706-3114
44302 EUR 236706-3112
44303 JAP 488307-4
44304 UK 236706-3112
44306 AUST 236706-3112
NOTE: View of transformer
(domestic LS-135 Pole Model):
See APPENDIX C for wiring schematic of
your country.
Reassembly Note:
Carefully align wires in groove to
prevent damage to insulation when
inserting pole in base.
LS 135 Floor Model