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SERVICE MANUAL

TUBE SEALER

Model SE250

Centron Technologies Corporation

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SERVICE MANUAL

TUBE SEALER

Model SE250

No. CAT.SE250SM1.1Ee

ISSUE 2 DEC. 2005

Manufactured by

Centron Technologies Corporation319-25 Sadang-4-dong, Dongjak-ku

Seoul, Korea 156-823Tel.+82.2.522.7807Fax+82.2.522.7806Website: www.centrons.com

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------------------------------------- Important Note

-------------------------------------

1. Safety notice:

This machine generates high radio-frequency (RF) power to melt blood bag tubing.

Users are requested to be cautious of potential electric shock or hazard.

The machine doesnt operate without the protector on the sealing head.

If the indication lamp color is amber, it indicates that the protector is removed

or not properly mounted on the sealing head. Check it and secure theprotector screw. The machine will not operate without the protector.

Always use the splashguard.

Do not insert fingers into the sealing head.

Only authorized and trained personnel should remove cover.

Always turn the power switch off before cleaning the machine.

2. Installation and Cautions:

a. Primary power requirement for Tube Sealer SE250 is marked on the rear panel.

Power outlet and power cord should be grounded ones.

b. Always keep the sealing head area clean and dry. If the sealing head becomes wet

or dirty, an arc may appear during the sealing process. If an arc appears, clean the

sealing head and let it dry thoroughly.

c. Use a soft cloth and mild detergent to clean the equipment. After cleaning, wait a

few minutes until the area cleaned is completely dry. DO NOT USE PAINT

THINNER, BENZENE, SOLVENT OR STRONG DETERGENT.

d. Avoid using or leaving the machine in a location where the temperature is higher

than 122 F (50 C). Keep it away from any heating source or direct sunlight.

i

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Contents

page

Important Note i

Contents ii

List of Figures iii

1. Introduction 1-1

1-1. General 1-1

1-2. Feature 1-3

1-3. Specification 1-4

2. Appearance and Function 2-1

3. System Description 3-1

3-1. General 3-1

3-2. Control Board 3-2

3-3. RF Board 3-3

3-4. Power Supply Module 3-3

3-5. Filter Board 3-3

3-6. Matching Board 3-33-7. Sealing Head Assembly 3-4

4. Standard Operating Procedure 4-1

4-1. Preparation for Sealing 4-1

4-2. Sealing Tubing 4-1

4-3. Thickness Adjustment 4-2

5. Troubleshooting 5-1

5-1. Precaution 5-15-2. Test Equipment 5-2

5-3. Troubleshooting Procedure 5-3

5-4. Sealing Time Adjustment 5-7

5-5. RF Adjustment 5-8

5-6. Replacing Fuse 5-10

5-7. Cleaning Sealing-Head 5-11

6. Schematic Diagram 6-1

ii

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page

7. Technical Illustration 7-1

8. Parts List 8-1

List of Figures page

[Figure 1-1] Tube Sealer SE250 1-2

[Figure 2-1] Appearance of SE250 2-1

[Figure 3-1] Overall system block diagram 3-1

[Figure 3-2] Control board functional block diagram 3-2

[Figure 3-3] RF board functional block diagram 3-3

[Figure 3-4] Sealing-head assembly functional block diagram 3-4

[Figure 5-1] Troubleshooting flow charts 5-4

[Figure 5-2] RF test set-up 5-8

[Figure 6-1] System wiring diagram 6-2[Figure 7-1] Exploded view of SE250 7-2

[Figure 7-2] Control board layout 7-3

[Figure 7-3] Distribution board layout 7-3

[Figure 7-4] RF board layout 7-4

[Figure 7-5] Filter board layout 7-5

[Figure 7-6] Matching board layout 7-5

[Figure 7-7] Trigger board layout 7-5

iii

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1 - 1

1. Introduction

1-1. General

This Service Manual covers all technical information of the Tube Sealer SE250 for

servicing and maintenance of the machine.

The manual contains ;

1. Introduction

2. Appearance and Function

3. System Description

4. Standard Operating Procedure

5. Troubleshooting Procedure6. Adjustments Procedure

7. Schematic Diagrams

8. Technical Illustration

9. Parts List

The Tube Sealer model SE250 is a precision electronic device. Troubleshooting and

repair must be carried by authorized service personnel.

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[Figure 1-1] Tube Sealer SE250

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1 - 3

1-2. Feature

The tube sealer model SE250 is a heavy-duty tube sealer for bench-top use. It provideseffective sealing of blood bag tubing in about one second. The machine generates

strong high-frequency power for a melting process called dielectric heating. When

blood bag tubing is placed into the sealing head, heat is generated between the

electrodes very quickly, so the tubing melts in about one second and then cools to form

a seal.

When the user places tubing into the sealing jaw, the sealing process is triggered. An

electrode comes out to press the tubing and, at the same time, heat is applied to the

tubing. After the tubing melts, the electrode retracts automatically. If a thicker or bigger

tubing is used, the sealing time may be longer. Even if a seal is not made, for safety, theelectrode will return to its original position automatically, in about 3 seconds from the

start.

An adjustment screw is located in the sealing head unit. The thickness of the seal can be

adjusted by turning the adjustment screw.

The sealing head area should be kept clean and dry always. If the sealing head becomes

wet or dirty, an arc may appear during the sealing process. To make cleaning easier, the

protector on the sealing head can be disassembled and reassembled without using any

tools. For safety reason, when the protector is removed from the sealing head, the

machine doesnt operate. The protector should be mounted in place on the sealing headafter cleaning.

A splashguard, made of a piece of transparent plastic sheet, is prepared on the top of the

sealing head.

A set of the machine includes the following items:

Main unit (1)

Power cord (1)

User's manual (1)

Spare fuses (2)Spare splashguards (5)

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1 - 4

1-3. Specification

a. Physical specification:

(1) Dimension (WxHxD): 175x150x300 mm (6.9"x5.9"x11.8")

(2) Weight: 6 Kg (13.3 lb)

b. Power source:

(1) AC main voltage: 100-120 or 220-240 VAC, 50/60 Hz, 1 phase

(the voltage range only as marked on the rear panel)

(2) Power consumption: Operating - 250 watts, standby - 10 watts

(3) Fuse rating: 3 Amperes when AC main is 100-120 VAC

2 Amperes when AC main is 220-240 VAC

c. Features:

(1) Tubing size to seal: 6 mm (1/4") diameter max.

(2) RF frequency: 40.68 MHz

(3) Output RF power: effective level - 30 watts

(4) Sealing time: 0.8 - 1.2 seconds nominal

(5) Lamp color indication: Green - Ready to seal

Red - Sealing in progress

Amber - Not ready to seal. Protector not in place

d. Temperature:

(1) Operating: 0 - 40 C (32 - 104 F)(2) Storage: -20 - 70 C (-4 - 158 F)

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2 - 1

2. Appearance and Function

[Figure 2-1] Appearance of SE250

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(1) Splashguard: It protects users eyes from blood in case that the tubing breaksduring

sealing. Loosen the screw above the splashguard, pull it forward, and secure the

screw. Splashguard is a disposable part.

(2) Indication lamp: This is a tri-color LED lamp, showing;

green - when the machine is ready to seal

red - when sealing is in progress

amber - when the protector is not in place, so the machine is not ready.

(3) Sealing head: Pushing the trigger lever down initiates a cycle of sealing. But forsafety reason, the trigger lever is disabled while the protector is removed from the

sealing head, so the machine doesnt start.

(4) Trigger lever: It initiates the sealing process, and controls the sealing head action as

well as the generation of high-frequency power.

(5) Adjustment screw: It controls the thickness of seals.

(6) Protector: It is a detachable cover attached with a screw. The protector can be

removed for cleaning of the sealing head. The protector should be mounted in placeafter cleaning. The machine doesn't operate without the protector on sealing head.

(7) Power switch: This switch turns the equipment power on and off.

(8) Fuse: The fuse holder houses a fuse.

(9) Power cord inlet: This accepts the power cord plug. A grounded power cord should

be used to avoid potential electric shock.

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3 - 1

3. System Description

3-1. General

Tube Sealer SE250 consists of five PCB assemblies, the sealing-head assembly and the

switching power supply unit. Refer to [Figure 3-1] to find overall system configuration.

[Figure 3-1] Overall System Block Diagram

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3 - 2

Control board assembly contains logic circuits and timing gates. It takes sensor outputsand command signals, and controls overall functions of this equipment.

RF board assembly is a high-power RF oscillator-amplifier. It generates RF energy and

sends the energy to sealing-head assembly through filter board assembly and matching

board assembly.

Sealing-head assembly is an electro-mechanical structure. It consists of a solenoid,

moving sealing electrode, trigger board assembly, micro-switches and a protector. For

safety reason, when the protector is removed from the sealing head, the machine

doesnt operate. The protector should be mounted in place on the sealing head after

cleaning.

On the front panel are an indication lamp on sealing-head and a power switch. An AC

inlet and a fuse holder are found at rear panel.

3-2. Control Board

Control board has a CPU that controls RF on/off and the solenoid.

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3 - 3

3-3. RF Board

RF board comprises an oscillator, drive amplifier stages and power amplifier, and

filter networks.

3-4. Power Supply Module

A switching-mode power supply module is used as an internal power converter.

The module takes either 220-240 VAC or 100-120 VAC as input, and provides

regulated voltage of 12VDC as output.

3-5. Filter Board

Filter board has two-stage low-pass filter circuit.

3-6. Matching Board

On the matching board is an impedance transformer, or called loading coil.

It transforms RF board impedance to sealing-head impedance.

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3-7. Sealing-Head Assembly

Sealing-head assembly comprises sealing electrode, trigger board assembly, solenoid,

trigger lever, micro-switches and the protector.

[Figure 3-4] represents the functional block diagram of sealing-head assembly.

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4 - 1

4. Standard Operating Procedure

4-1. Preparation for Sealing

(1) Connect power cord to a wall outlet.

(2) Check that the sealing-head protector has installed.

(3) Turn power switch on.

The indication lamp should be green.

If the lamp color is amber, it indicates that the protector is removed or

not properly mounted on the sealing head. Check it and secure theprotector screw. The machine doesnt work without the protector.

(4) Loosen the splashguard screw and position the splashguard on the sealing head.

Tighten the screw.

4-2. Sealing Tubing

(1) Holding one end of the tubing to be sealed in each hand, place the tubing into thesealing jaw and depress the trigger lever. This action will:

cause the moving electrode to clamp tubing,

apply heat to melt the tubing,

turn the lamp color to red.

(2) In about 1 to 3 seconds, the moving electrode retracts.

Tubing is now sealed.

The lamp shows green.

(3) Remove tubing from the sealing jaw.

(4) Inspect tubing seals.

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4 - 2

4-3. Thickness Adjustment

Users can adjust the thickness of seals by simply turning the adjustment screw on the

sealing head. Turn the screw slowly and check adjustments often. Slight turns of the

screw can make significant changes in the seal.

(1) Loosen the screw under the protector and remove the protector.

(2) With a thin flat-tip screwdriver, turn the adjustment screw located to the left of the

sealing head.

Turn it clockwise to make the seal thicker and narrower.

(Sealing time will take shorter.)

Turn it counter-clockwise to make the seal thinner and wider.(Sealing time will take longer.)

[Note] One full turn can change the thickness as much as 0.5 mm.

(3) Replace the protector and make a few seals to check the thickness and adjust

again as required.

(4) When the tubing seal thickness and width is satisfactory, replace the protector and

fasten the protector screw.

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5 - 1

5. Troubleshooting

This Chapter 5 describes how to check and troubleshoot the equipment by authorized

service personnel with proper test equipment.

Troubleshooting flow chart leads service personnel to a faulty assembly or to one or a

few suspicious components. When a faulty assembly or component is isolated, it

would be adjusted in accordance with the procedures in this chapter, or be replaced

with a good one.

Followings are the topics covered in this chapter ;

. Precautions for troubleshooting

. Test equipment necessary

. Troubleshooting flow charts

. Adjustments of major characteristics

. Cleaning of sealing-head section.

5-1. Precaution

When performing troubleshooting, keep following general precaution ;

* Use proper test equipment and tools.

* Be careful enough not to touch any AC main line.

* Set a current limit at the DC power supply to protect RF power transistor.

* Prepare sufficient heatsink for RF board to avoid temperature increase.

* When replacing a component, use proper rated component.

* Be careful not to touch RF circuits and electrodes with your finger when RF is

being generated. You may be shocked and burnt.

Dangerous high voltage over one hundred volts may exist at RF circuits

while RF is turned on.

Finger may be burnt by induction heating if it's placed between two

electrodes of the sealing-head, or near RF transistors and transformers.

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5 - 2

5-2. Test Equipment

Test equipment and tools listed below are necessary to do troubleshooting.

(1) Minimum test equipment and tools for troubleshooting ;

Multimeter

Regulated DC power supply (12 volts/20 amperes)

Oscilloscope (10 MHz)

Frequency counter (100 MHz)

RF power meter (100 MHz/200 Watts)

Screwdrivers (cross-tips, flat-tips)

(2) More test equipment necessary for complete troubleshooting ;

DC Ammeter (20 amperes)

Regulated DC power supply (12 V/20 A, with current-limiting feature)

Oscilloscope (100 MHz, dual-trace)

Spectrum analyzer (300 MHz)

Network analyzer (S-parameters, Impedance-curve display feature)

RF power meter (200 Watts, forward/reverse/effective powers)

RF dummy load (50 ohm, 100 W)

RF attenuator (60 DB)

Coaxial cables (RG-58, BNC male-BNC male)

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5 - 3

5-3. Troubleshooting Procedure

The troubleshooting flow charts in [Figure 5-1] will guide service personnel to a faulty

assembly or components that should be replaced or corrected. When a faulty assembly

is isolated, it will be adjusted to correct state, or be replaced with a new good assembly.

In case that service people have good knowledge in electronics, proper test equipment

and components, they can troubleshoot to a single faulty component.

All technical documentation necessary for adjustments and troubleshooting are

prepared in the Chapters 6, 7 and 8.

Legend of Troubleshooting Flow Chart

Square .......... Action

Diamond .......... Decision

A Circle .......... Connection to/from other branch.

Vertical line .......... "YES" path

Horizontal line ...... "NO" path

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[Figure 5-1] Troubleshooting Flow Chart (Page 2/3)

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[Figure 5-1] Troubleshooting Flow Chart (Page 3/3)

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5 - 7

5-4. Sealing Time Adjustment

Sealing time varies by such factors as RF power, tube thickness, electrode temperature,room temperature, number of seals made consecutively, etc.

As explained in Section 3-2, sealing time starts when the trigger lever is depressed by

a tube inserted to be sealed, and ends when the tube melts then moving electrode is

pushed completely. Thinner tube or warmer electrode takes less sealing time.

If a tube is too thick or made of non-thermoplastic material, the electrode cannot be

pushed outward. But RF generation continues.

For safety reason, sealing time ends by itself automatically after certain time elapsed.

The maximum sealing time is fixed by sealing time gate generated in Control board.0.8 - 1.2 seconds is a nominal sealing time for a tube in standard size in normal room

temperature. "Sealing time gate" is fixed at about 3 seconds.

(1) Sealing time gate adjustment ;

Although it is not recommended, sealing time gate can be varied by changing a fixed

resister R22 on the Control board when it's necessary to be done with any reason.

(2) Sealing time adjustment ;

As explained above, sealing time ends when the tube melts then sealing electrode is

pushed outward completely. A microswitch in the unit is pushed and it sends out a

"limit" signal to stop the ongoing sealing gate.The timing to press "limit" microswitch can be changed easily by turning a screw on

the front panel. This adjustment changes thickness of sealed points.

Refer to Section 4-3.

Experiments show that best adjustment of limit-switch screw position is that the switch

would be activated 0.2 - 0.4 mm before moving electrode contacting to opposite metal

electrode.

Use thickness gauges of 0.2 mm and 0.4 mm thick to calibrate the point.

Adjust the screw till following is fulfilled ;

When 0.2 mm gauge is inserted to push trigger lever, electrode moves toopposite metal electrode but returns immediately. This means limit-switch is

activated.

When 0.4 mm gauge is inserted to push trigger lever, electrode moves to

opposite metal electrode and holds the gauge for about 3 seconds, then returns.

This means limit-switch is not activated.

Plain sheets of paper can be used as a simple thickness gauge as thickness of a paper

sheet is about 0.1 mm.

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5 - 8

5-5. RF Adjustment

Following procedures describe standard check procedures for the RF circuitry.Refer to [Figure 5-2] below for test set-up and [Figure 7-4] for board layout.

[Figure 5-2] RF Test Set-up

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5 - 9

(1) Set up test equipment as per the [Figure 5-2].

(2) Set the DC power supply at 12 volts.

Be sure to set a current-limit of the power supply at 20 amperes.

* CAUTION *

Failure to set current-limiter may cause RF transistors blown up.

(3) If following tests are to be done with RF board assembly taken out from its

original location, prepare sufficient heat sinks and a cooling fan to avoid excess

temperature rise at transistors and transformers on RF board.

* CAUTION *

Minimum heat dissipation gears to be prepared shall be 100 watts.

Failure to prepare sufficient heatsink for RF board assembly may cause the RF

transistors blown up.

(4) Set RF power meter, attenuator and spectrum analyzer at proper ranges to check

40.68 MHz power of 150 watts maximum.

(5) Turn on sealer power switch.

(6) Every time when you need to measure any characteristics of RF circuit fromfollowing paragraph (7), push trigger lever at sealing-head or make short-circuit

at control board between P2-pin4 and ground to trigger RF generation.

* CAUTION *

NEVER supply continuous power for more than ten seconds unless sufficient

heatsink are prepared.

(7) Watch power meter and spectrum analyzer. You should have more than 90 watts

when a 50-ohm dummy load is connected at 40.68 MHz.

If you would have no oscillation, turn transformer T1 slowly until oscillation starts.

Set T1 at mid point of the adjustable ranges where you have oscillation.

(8) Read power meter.

Be sure to read effective power when a sealing gun unit is connected as RF load.

Effective power is calculated as (forward power) - (reverse power).

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* NOTE 1 *

When a sealing-head is connected, power varies greatly according to electrode gapdistance and what is loaded in between sealing electrodes.

Best is to use a real tubing but it gives difficulty to take stable reading.

Using paper sheets of 1.0 mm thick will give similar reading with stability.

It would be good if effective power would be not less than 30 watts.

* NOTE 2 *

Watch the ammeter to read supply current. Normal current will be less than 15 A

when a dummy load is connected. When a sealing-head is connected, maximum

current could be as high as 18 Amperes.

(9) If RF board would not function properly, really there is not much thing to do.

What you can do on the board is ;

a. Just examine the board by eyes to find any part is burnt or badly soldered.

b. Adjust transformer T1 as paragraph (7) above to get stable oscillation.

c. Touch to alter shapes of the coil L2 and L4 to change power level a little.

* NOTE 3 *

Even if a drive amplifier or a power amplifier transistor or a transformer is bad,

oscillation may not exist. So a transistor or a transformer should be determined

to be replaced only by checking the component individually by some method of

direct measurement.

(10) Turn power off and disconnect test equipment.

5-6. Replacing Fuse

A fuse is used. It is contained in the fuse holder on rear panel of the machine.

Type : Fast-acting fuse (20 mm long, 5 mm diameter, circular tube type)

Rating :

Power source voltage Fuse amperage

100-120 VAC 3 Amps

220-240 VAC 2 Amps

Replacement procedure:

(1) Turn the power switch off.

(2) Remove power cord from wall outlet and cord inlet on rear panel.

(3) With a flat-tip screw, open the fuse holder cap on rear panel by turning it counter-

clockwise.

(4) Replace the blown fuse with a new one with the same amperage.

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5 - 11

(5) Close fuse holder cap securely.

(6) Connect power cord.

(7) Turn the power switch on and test sealer.

5-7. Cleaning Sealing-Head

The sealing head, electrodes and trigger lever can easily be stained by dust, spilled or

leaked blood or blood components. FREQUENT CLEANING WILL OFFER YOU

THE BEST LONG TERM RESULTS. Never put sharp objects or metal objects on

sealing head electrodes as they can easily be marred.

For proper cleaning, use a dry cloth or a cloth dampened with water. A mild detergent

may be used. Thoroughly dry the sealing head area before applying power. If thesealing head is wet when RF energy is applied, an arc may appear.

Follow the decontamination procedure of your facility when a blood spill occurs.

Avoid spraying liquids on the sealing head.

Cleaning procedure:

(1) Turn power switch off.(2) Loosen the screw under the protector and remove the protector.(3) Clean the sealing head and trigger lever carefully as described above.Dry the sealing head thoroughly.(4) Loosen the screw above the splashguard and clean it, or dispose of it and use a

new one.

(5) Reassemble the protector and protector screw.(6) If you have used water, detergent or decontamination liquid, wait for a few

minutes to allow for thorough drying.

(7) Turn power switch on. The machine is ready to use.(8) Test sealer.

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6 - 1

6. Schematic Diagram

[Figure 6-1] System wiring diagram

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6 - 2

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7. Technical Illustration

[Figure 7-1] Exploded view of SE250

[Figure 7-2] Control board layout

[Figure 7-3] Distribution Board Layout

[Figure 7-4] RF board layout

[Figure 7-5] Filter board layout

[Figure 7-6] Matching board layout

[Figure 7-7] Trigger board layout

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[Figure 7-1] Exploded View of SE250

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[Figure 7-2] Control Board Layout

[Figure 7-3] Distribution Board Layout

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[Figure 7-4] RF Board Layout

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[Figure 7-5] Filter Board Layout

[Figure 7-6] Matching Board Layout

[Figure 7-7] Trigger Board Layout

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8 - 1

8. Parts List

Each part is identified with manufacturer's part number in the Parts List.

Part location in units is found by the find number in [Figure 7-1] Exploded view, or in a

circuit board layout in [Figure 7-2] through [Figure 7-7].

Prefix "A" in the find number denotes that it is not a single component but an assembly,

and a lower-level parts list of which is presented at another place.

Ordering for a service part to distributor or manufacturer should be accompanied by its

part number, or a module designation number if it is an independent unit.

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