Welch Allyn GS-777 User manual

Welch Allyn GS 777 Wall
Transformer

Service manual

© 2012 Welch Allyn. All rights are reserved. To support the intended use of the product described in this publication,
the purchaser of the product is permitted to copy this publication, for internal distribution only, from the media
provided by Welch Allyn. No other use, reproduction, or distribution of this publication, or any part of it, is permitted
without written permission from Welch Allyn. Welch Allyn assumes no responsibility for any injury to anyone, or for
any illegal or improper use of the product, that may result from failure to use this product in accordance with the
instructions, cautions, warnings, or statement of intended use published in this manual.

Welch Allyn is a registered trademark of Welch Allyn.

For information about any Welch Allyn product, call Welch Allyn Technical Support:

USA

[phone]

Australia

[phone]

[phone]

Canada

European Call Center

Germany

Malaysia

Singapore

United Kingdom

Material Number 718860 Ver. B

[phone]
[phone]
[phone]

Japan

[phone]
[phone]
[phone]

Spain

[phone]
[phone]

China

France

Italy

Latin America

Netherlands
South Africa

Sweden

[phone]
[phone]
[phone]
[phone]
[phone]
[phone]
[phone]

Welch Allyn, Inc.
4341 State Street Road
Skaneateles Falls, NY 13153-0220 USA

www.welchallyn.com

Regulatory Affairs Representative
Welch Allyn Limited
Navan Business Park
Dublin Road
Navan, County Meath
Republic of Ireland

© 2012 Welch Allyn. All rights are reserved. To support the intended use of the product described in this publication,
the purchaser of the product is permitted to copy this publication, for internal distribution only, from the media
provided by Welch Allyn. No other use, reproduction, or distribution of this publication, or any part of it, is permitted
without written permission from Welch Allyn. Welch Allyn assumes no responsibility for any injury to anyone, or for
any illegal or improper use of the product, that may result from failure to use this product in accordance with the
instructions, cautions, warnings, or statement of intended use published in this manual.

Welch Allyn is a registered trademark of Welch Allyn.

For information about any Welch Allyn product, call Welch Allyn Technical Support:

USA

[phone]

Australia

[phone]

[phone]

Canada

European Call Center

Germany

Malaysia

Singapore

United Kingdom

Material Number 718860 Ver. B

[phone]
[phone]
[phone]

Japan

[phone]
[phone]
[phone]

Spain

[phone]
[phone]

China

France

Italy

Latin America

Netherlands
South Africa

Sweden

[phone]
[phone]
[phone]
[phone]
[phone]
[phone]
[phone]

Welch Allyn, Inc.
4341 State Street Road
Skaneateles Falls, NY 13153-0220 USA

www.welchallyn.com

Regulatory Affairs Representative
Welch Allyn Limited
Navan Business Park
Dublin Road
Navan, County Meath
Republic of Ireland

Contents

Symbol descriptions ............................................................................... 1

Safety ....................................................................................................... 3

Overview .................................................................................................. 5

v

General warnings and cautions ..................................................................................................... 3

General safety considerations ........................................................................................................ 4

Electrostatic discharge (ESD) ......................................................................................................... 4

Purpose and scope ........................................................................................................................... 5

Technical support services ............................................................................................................. 5

Service options .................................................................................................................................. 5

Repairs ................................................................................................................................................ 6

Returning products ........................................................................................................................... 6

Controls, indicators, and connectors ..................................................... 9

Troubleshooting .................................................................................... 11

Symptoms and solutions ................................................................................................................ 13

Disassembly and repair ........................................................................ 15

Required tools and equipment ...................................................................................................... 15

Remove rear housing, handles, circuit board, cradle wire harnesses, and cradles ........... 15

Functional verification and calibration ................................................ 19

Functional verification tests .......................................................................................................... 19

Verify functionality .......................................................................................................................... 19

Field replaceable units .......................................................................... 21

GS 777 Wall Transformer ............................................................................................................... 21

Appendices ............................................................................................ 23

Decontamination and cleaning requirements ............................................................................ 23

vi Contents Welch Allyn GS 777 Wall Transformer

Symbol descriptions

AC input power

DC input power

1

DC output power

Separate Waste Electronic and Electrical Equipment (WEEE) from other disposables.
Prepare this product for reuse or separate collection as specified by the WEEE
Directive 2002/96/EC or local law.

The product does not contain hazardous substances above threshold values defined
in China Standard SJ/T 11363 – 2006. The product is green and environmental and can
be recycled after use.

Illuminated: Power is present. Not illuminated: No power.

Type BF applied part

2 Symbol descriptions Welch Allyn GS 777 Wall Transformer

Safety

3

All users of the device must read and understand all safety information presented in this manual
before using or repairing the device.

United States federal law restricts this device to sale, distribution, or use by or on the order of a
licensed medical practitioner.

General warnings and cautions

WARNING Read and understand the instructions before using this product.
Failure to understand the operating requirements for this product can result in injury
to you or the patient and can damage the product.

WARNING Explosion hazard. Do not operate this product in the presence of
flammable anesthetics or other flammable substances in combination with air,
oxygen-enriched environments, or nitrous oxide.

WARNING Electric shock hazard. Do not simultaneously touch the patient and
the center metal contact of the handle.

WARNING Do not modify this equipment. Any modification of this equipment can
lead to patient injury. Any modification of this equipment voids the product
warranty.

WARNING Welch Allyn is not responsible for the integrity of any mounting
installation. Welch Allyn recommends that customers contact their Biomedical
Engineering Department or maintenance service to ensure professional installation
for safety and reliability of any mounting accessory.

Caution As a precaution, avoid using this product in close proximity to other
equipment. The product complies with current required standards for
electromagnetic interference and should not present problems to other equipment
or be affected by other devices.

Caution Only authorized Welch Allyn Service Centers can perform service on this
product.

Caution To make sure that the transformer can be unplugged from the AC power
source, never block access to the wall socket.

Caution Rx only (for professional use).

4 Safety Welch Allyn GS 777 Wall Transformer

Caution Do not autoclave the system. Autoclave accessories only if the

manufacturer’s instructions clearly approve it.

General safety considerations

• To ensure patient safety, use only accessories recommended or supplied by Welch Allyn.
Always use accessories according to your facility’s standards and according to the
manufacturer’s recommendations and instructions. Always follow the manufacturer’s
directions for use.

• Welch Allyn recommends that only Welch Allyn service personnel or an authorized repair
center perform warranty service. Performing unauthorized service on a device that is within
warranty may void the warranty.

Electrostatic discharge (ESD)

Caution Electrostatic discharge (ESD) can damage or destroy electronic
components. Handle static-sensitive components only at static-safe workstation.

Caution Assume that all electrical and electronic components of the device are
static-sensitive.

Electrostatic discharge is a sudden current flowing from a charged object to another object or to
ground. Electrostatic charges can accumulate on common items such as foam drinking cups,
cellophane tape, synthetic clothing, untreated foam packaging material, and untreated plastic bags
and work folders, to name only a few.

Electronic components and assemblies, if not properly protected against ESD, can be permanently
damaged or destroyed when near or in contact with electrostatically charged objects. When you
handle components or assemblies that are not in protective bags and you are not sure whether
they are static-sensitive, assume that they are static-sensitive and handle them accordingly.

Perform all service procedures in a static-protected environment. Always use techniques and

•
equipment designed to protect personnel and equipment from electrostatic discharge.

• Remove static-sensitive components and assemblies from their static-shielding bags only at
static-safe workstations—a properly grounded table and grounded floor mat—and only when
you are wearing a grounded wrist strap (with a resistor of at least 1 megohm in series) or other
grounding device.

• Use only grounded tools when inserting, adjusting, or removing static-sensitive components
and assemblies.

• Remove or insert static-sensitive components and assemblies only with device power turned
off.

• Insert and seal static-sensitive components and assemblies into their original static-shielding
bags before removing them from static-protected areas.

• Always test your ground strap, bench mat, conductive work surface, and ground cord before
removing components and assemblies from their protective bags and before beginning any
disassembly or assembly procedures.

Overview

Purpose and scope

This service manual is a reference for corrective service procedures for the Welch Allyn GS 777
Wall Transformer. It is intended for use only by trained and qualified service personnel.

Corrective service is supported to the level of field-replaceable units. These include circuit-board
assemblies and some subassemblies, case parts, and other parts.

5

WARNING When performing a service procedure, follow the instructions exactly

as presented in this manual. Failure to do so could damage the device, invalidate
the product warranty, and lead to serious personal injury.

Caution No component-level repair of circuit boards and subassemblies is
supported. Use only the repair procedures described in this manual.

This manual applies only to this device. For servicing of any other device, see the service manual
for the specific device.

Service work not described in this manual must be performed by qualified service personnel at the
factory or at an authorized Welch Allyn service center.

Technical support services

Welch Allyn offers the following technical support services:

Telephone support

•

• Replacement service parts

• Product service

For information on any of these services, call the Welch Allyn Service Center nearest you.

Service options

Warranty service

All repairs on products under warranty must be performed or approved by Welch Allyn. Refer all
warranty service to Welch Allyn Product Service or another authorized Welch Allyn Service
Center. Obtain a Return Material Authorization (RMA) number for all returns to Welch Allyn
Product Service.

6 Overview Welch Allyn GS 777 Wall Transformer

Caution Unauthorized repairs will void the product warranty.

Non-warranty service

Welch Allyn product service and authorized service centers support non-warranty repairs. Contact
any Welch Allyn regional service center for pricing and service options.

Welch Allyn offers modular repair parts for sale to support non-warranty service. This service must
be performed only by qualified end-user biomedical/clinical engineers using this service manual.

Repairs

A Welch Allyn Service Center must perform all repairs on products under warranty.

Caution Unauthorized repairs will void the product warranty.

Qualified service personnel or a Welch Allyn Service Center should repair products out of
warranty.

If you are advised to return a product to Welch Allyn for repair or routine maintenance, schedule
the repair with the service center nearest you.

Welch Allyn Technical Support

If you have a problem with the device that you cannot resolve, call the Welch Allyn Technical
Support Center nearest you for assistance. A representative will assist you in troubleshooting the
problem and will make every effort to solve the problem over the phone, avoiding a potential
unnecessary return.

If your product requires warranty or non-warranty repair service, a Welch Allyn Technical Support
representative will record all necessary information to issue an RMA number. The support
representative will provide you with the address of the Welch Allyn Service Center to send your
device to.

Technical support is available during local business hours.

Returning products

Note Welch Allyn does not accept returned products without an RMA.

When returning a product to Welch Allyn for service, please include the following information:

A complete return shipping address.

•

• A contact name and phone number.

• Any special shipping instructions.

• A purchase-order number or credit-card number if the product is not covered by a warranty.

• A full description of the problem or service request.

1. Contact Welch Allyn and request a Return Material Authorization number.

2. Ship the device to Welch Allyn, observing these packing guidelines:

a. Put the system and a packing list into the original shipping carton with the original

packing materials or into another appropriate shipping carton.

Service manual Overview 7

b. Write the Welch Allyn RMA number with the Welch Allyn address on the outside of the

shipping carton.

Note To ensure safe receipt of your system by the service center and to

expedite processing and return of the system to you,thoroughly

clean all residues from the device before you ship it to
Welch Allyn. For decontamination and cleaning requirements, see

“Decontamination and cleaning” in the appendices.
If a returned device is found to be contaminated with bodily fluids, it
will be returned at the owner’s expense. United States federal
regulations prohibit the processing of any device contaminated with
blood-borne pathogens. Welch Allyn thoroughly cleans all returned
systems on receipt, but any system that cannot be adequately
cleaned cannot be repaired.

8 Overview Welch Allyn GS 777 Wall Transformer

Controls, indicators, and connectors

Front view

9

No. Feature Description

1 Physical assessment instruments -

Handles and handle cradles

2 Rheostat Located on each handle. Turn clockwise to increase light

3 LED indicator Indicates power is present.

4 USB power cable Twin USB power cable

5 5W power supply with LED indicator 5W platform power supply. Indicates power is present.

6 5W adapter plug Region-specific 5W adapter plug

Handles will accept any 3.5V Welch Allyn instrument head.
The handle cradles support using one handle at a time. A

handle turns on automatically when you remove it from a
cradle and turns off when you return it.

output; turn counterclockwise to decrease light output.

10 Controls, indicators, and connectors Welch Allyn GS 777 Wall Transformer

Back view

No. Feature Description

1 Host USB mini, power in 5V USB, type "mini". Provides power to the GS 777 Wall

Transformer.

2 Host USB, power out 5V USB, type "A". Provides power to other supported Welch

Allyn devices.

Troubleshooting

This section provides a process diagram to help you troubleshoot the device. Follow it first and
then refer to the accompanying tables.

11

This section provides the following tables to help you troubleshoot the device.

Symptoms and solutions: These tables list symptoms you might observe, list possible

•
causes, and suggest actions that might eliminate the problem.

These tables can help you diagnose and fix a problem. They do not replace basic troubleshooting
skills. You must still trace the source of the problem to the board or module level to decide the best
course of action.

Welch Allyn does not support component-level repair to the board or module.

For available replacement parts, see “Field Replaceable Units.”

WARNING Do not perform troubleshooting on a device that is emitting smoke or
exhibits other signs of excessive overheating. Disconnect the device from AC
power and call Welch Allyn Technical Support immediately.

12 Troubleshooting Welch Allyn GS 777 Wall Transformer

Caution Replace parts, components, or accessories only with parts supplied or

approved by Welch Allyn. The use of any other parts can lead to inferior
performance and will void the product warranty.

Service manual Troubleshooting 13

Symptoms and solutions

Handles

Symptom Possible cause Suggested action

The lamp does not illuminate There is no lamp in the handle head Install a lamp in the handle head.

The lamp is burned out Install a new lamp.

The other handle is off the cradle Place the other handle in the

cradle.

The system is not powered up Power up the system.

The PCBA is defective Replace the PCBA.

The handle assembly is defective Replace the handle assembly.

The lamp is too dim The rheostat setting is too low Increase the rheostat setting.

The PCBA is defective Replace the PCBA.

The handle assembly is defective Replace the handle assembly.

The lamp is too bright The rheostat setting is too high Decrease the rheostat setting.

The PCBA is defective Replace the PCBA.

The handle assembly is defective Replace the handle assembly.

The lamp brightness does not
adjust

The handle becomes very hot to the
touch

The PCBA is defective Replace the PCBA.

The handle assembly is defective Replace the handle assembly.

The lamp has been on for an
extended period of time

Return the handle to the cradle.

Note The GS 777 Wall Transformer will accommodate instrument heads of the Welch Allyn

approved Halogen and LED type bulbs without any manual adjustment. For information about
instrument heads, follow the instructions provided in their directions for use.

14 Troubleshooting Welch Allyn GS 777 Wall Transformer

Disassembly and repair

These procedures provide instructions for system disassembly and board removal. Except where
otherwise noted, the assembly procedure is the reverse of the disassembly procedure.

Each procedure may include the following:

Reassembly notes: This contains information specific to reassembly not addressed in the

•
disassembly instructions.

15

WARNING Electrical shock hazard. Disconnect power before opening the device.

Caution Before disassembling the device, disconnect the USB power cord and

any attached accessories.

Caution Perform all repair procedures at a static-protected station.

Caution When the system case is opened, regard all parts as extremely fragile.

Execute all procedure steps with care and precision.

Caution Observe screw torque specifications, especially with screws that secure
directly into plastic standoffs.

Caution To avoid mismatching screws and holes, keep the screws for each piece
with that piece as you remove modules and circuit assemblies.

Required tools and equipment

• Screw driver calibrated for 7.5 in-lb ±0.5 in-lb

○

#2 Phillips bit

• Torque driver calibrated for 7.5 in-lb ±0.5 in-lb

○

#10 Torx bit

• Needle-nose pliers

Remove rear housing, handles, circuit board, cradle wire harnesses, and cradles

Remove the rear housing

Disconnect the USB power cord and any attached accessories.

a. Remove the device from the wall.

16 Disassembly and repair Welch Allyn GS 777 Wall Transformer

b. Disconnect the USB cable.

c. Remove the rear housing by removing the four large Phillips screws.

d. Lift and remove the rear housing.

Remove the handles

Disconnect the handle connector wires from the PCBA.

e.

Service manual Disassembly and repair 17

f. Lift and remove the handle cables from the front handle housing.

Reassembly note When reconnecting the handle connection wires to the handle
PCBA, the connecting wires must be facing up and away from the PCBA.

Remove the circuit board

Disconnect the two IR wire connectors from the Circuit board.

g.

h. Remove the three torx screws.

i. Lift and remove the Circuit board.

Reassembly note When reconnecting the IR wire connectors to the handle PCBA, the
connecting wires must be facing down and toward the cradle assemblies.

18 Disassembly and repair Welch Allyn GS 777 Wall Transformer

Remove the handle cradle and optical assemblies

j. On the rear of the assembly, disconnect both IR wires from the optical sensors.

k. Push in the snap tabs and then remove the cradle assembly by pushing outward.

Reassembly note For ease of assembly, connect the IR wire assemblies to the optical
sensors before attaching the handle cradle to the handle assembly housing.

• Attach the connector with the black and white wires to the optical detector
(indicated by the letter "B" molded into the cradle plastic). Attach the connector with
the red and white wires to the optical emitter. The wires should face inward once the
handle cradle is assembled.

l. Snap the handle cradle assembly into the front housing. Make sure that the cradle

assembly tab and the beveled edge are at the top of the housing.

Functional verification and calibration

Functional verification tests

The functional verification tests help to confirm the proper operation of the device and its options.
These tests support the requirements of routine preventive maintenance. It is not necessary to
disassemble the device to perform these tests.

19

The tests may also be useful as a diagnostic tool to help isolate a malfunction.

Verify functionality

To verify functionality:

Connect power to the device and ensure the power LED indicator is illuminated.

1.

2. Attach a working instrument head to each handle assembly.

3. Remove a handle from the cradle and verify illumination.

4. Test the handle rheostat to ensure illumination adjusts from minimum to maximum output.

5. Return the handle to the cradle.

6. Repeat for the remaining handle.

The instrument heads should automatically turn off when returned to the cradle.

20 Functional verification and calibration Welch Allyn GS 777 Wall Transformer

Field replaceable units

This listing includes only field-replaceable service parts. Product accessories—including 3.5V
instrument heads and other consumable items—are listed separately in the accessories list in the
device’s directions for use, which is available from Welch Allyn Customer Service.

GS 777 Wall Transformer

21

Kit part numbers

No. part numbers Item

1 104299 SK, KIT HANDLE ASSEMBLY

2 408514 PCBA 777 WALL TRANSFORMER

3 105062 SK, ASSY, CRADLE, 2PC BLUE

4 104992 SK, 777 FRONT W/LIGHT PIPE

5 104993 SK, 777 TWIN REAR HSG

(Not Illustrated)

(Not Illustrated)

408781 777 WALL MOUNTING KIT

104281 SK, IR CONNECTOR & WIRE ASSY

22 Field replaceable units Welch Allyn GS 777 Wall Transformer

No. part numbers Item

1 104713 TWIN USB POWER CABLE

2 104996 SK, 5W PLATFORM POWER SUPPLY

3 713263 5W ADAPTER PLUG US

713264 5W ADAPTER PLUG UK

713265 5W ADAPTER PLUG EURO

713266 5W ADAPTER PLUG AUS

715162 5W ADAPTER PLUG CHINA

715163 5W ADAPTER PLUG S. AFRICA

Appendices

Decontamination and cleaning requirements

As a general safety precaution, the device must undergo decontamination before being returned to
Welch Allyn for service, repair, inspection, or disposal.

Note Contaminated items must not be returned without prior, written agreement.

23

Note Decontaminate the device according to your facility’s procedures and local

regulations.

Cleaning is an essential prerequisite for effective disinfection or decontamination.

Note The following guidelines apply to the device only. For peripheral items, follow the

cleaning instructions in the directions for use that accompany these accessories.

WARNING Before you clean the GS 777 Wall Transformer, unplug it from the wall
socket.

WARNING Electric shock hazard. DO NOT autoclave the GS 777 Wall
Transformer or accessories.

WARNING Liquids can damage electronics inside the GS 777 Wall Transformer.
Prevent liquids from spilling on or dripping into the GS 777 Wall Transformer. If
liquids are spilled on or drip into the GS 777 Wall Transformer:

1. Disconnect the power plug.

2. Remove the GS 777 Wall Transformer from the wall.

3. Dry off excess liquid from the GS 777 Wall Transformer.

4. Mount the GS 777 Wall Transformer on the wall.

5. Verify that the GS 777 Wall Transformer functions normally before using it.

Clean the GS 777 Wall Transformer on a routine basis according to your facilities protocols and
standards or local regulations.

To clean the GS 777 Wall Transformer (excluding the instrument heads), use any of the following:

A clean cloth slightly dampened with 70 percent isopropyl alcohol or 10 percent chlorine

•
bleach solution. Wipe dry with a clean cloth.

• Sani-Cloth® Plus.

• CaviWipes™ (see caution below).

24 Appendices Welch Allyn GS 777 Wall Transformer

Caution Do not use CaviWipes to clean the blue handle cradles. This cleaning

agent produces bubbles and liquid during the cleaning process that can enter
openings in the cradles and limit handle performance for as long as 30 minutes after
cleaning.

To clean the instrument heads, follow the instructions provided in their directions for use.