Service Guide GHT-502D
SERVICE GUIDE
KYE SYSTEMS CORP.
GHT-502D
Version : 1.0
Version : 1.0 Page 1 of 18
Service Guide GHT-502D
Revision History
Version Date Change
1.0 11/05/2004
Version : 1.0 Page 2 of 18
Service Guide GHT-502D
Table of Contents
Revision History …………………………………………………………………….2
Table of Contents ……………………………………………………………………3
Getting Started ………………………………………………………………………4
Conventions Used in this Guide ……………………………………….4
Safety Precautions ……………………………………………………..4
Chapter 1. How to Handle Defective Returns……………………………………..5
1.1 Overview …………………………………………………………..5
1.2 Problems …………………………………………………………...6
1.2.1 FL/FR, RL/RR channels no sound …………………7
1.2.2 CEN channel no sound………….……………....…8
1.2.3 Woofer channel no sound....……………...………..8
1.2.4 Decoder no power…………………………………9
Chapter 2. Specifications …………………………………………………………10
Chapter 3. Block Diagram ……………………………………………………….12
Chapter 4. Exploded View ……………………………………………………….13
Chapter 5. Part List ………………………………………………………………15
Chapter 6. Schematic Diagram …………………………………………………...17
Chapter 7. Important Notes ………………………………………………………18
7.1 Packing Requirement for Sending the PCB Assembly by Post …..18
7.2 Short of Spare Parts while Repairing a Speaker System …………18
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Service Guide GHT-502D
Getting Started
Conventions Used in this Guide
Pay Special Attention : Instructions that are important to remember and
may prevent mistakes .
Caution : Information that, if not followed, may result in damage to the
product .
Safety Precautions
The following precautions should be observed in handling the speaker
Described in this guide :
Place the speakers on a flat, level and stable surface.
Do not place the speakers in environments subject to mist, smoke,
vibration, excessive dust, salty or greasy air, or other corrosive gases
and fumes.
Do not drop or jolt the speakers.
Do not allow anything to drop into the subwoofer case through its
ventilator, as it could result in fatal electric shock or fire .
Place the unit far enough from other equipments for good heat
dissipation .
Disconnect the AC power cord from the AC outlet before performing
any maintenance on the speakers .
Do not perform any maintenance with wet hand .
Prevent foreign substances, such as water, other liquids or chemicals ,
From entering the speakers while performing maintenance procedures
on the speakers .
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Service Guide GHT-502D
Chapter 1. How to Handle Defective Returns
1.1 Overview
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Verifying problems
Proceeding necessary tests
Receiving Defective speakers from
Customers
Analyzing possible malfunction
causes
Deciding & proceeding the
rectification methods
Replace necessary defective parts
Proceeding tests to
Verif
y
if the speaker is
functionin
g
normall
y
repackaging to customers
Function NG
Function OK
Function OK
Function NG
Service Guide GHT-502D
1.2 Problems
Item Problem Description
1.2.1 FL/FR, RL/RR channels no sound
1.2.2 CEN channel no sound
1.2.3 Woofer channel no sound
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1.2.4 Decoder no power
Service Guide GHT-502D
Attention
1.2.1 FL/FR , RL/RR channels no sound
Problem
Solutions
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Please follow the numbered sequence marked within parenthesis given in individual
Flow chat, in that this is the best-recommended sequence to rectify the problems .
FL/FR,RL/RR channels no sound
Broken or short circuit
Defective C505-508,U501 ,
C501-C504,U901
Speaker cable dis-connect or
speaker damaged
Check solder points on
PCB
Check and Replace
defective IC or
Component
Re-connect speaker cable or
replace defective speaker(s)
Analyzer and
Identify the Causes
Service Guide GHT-502D
1.2.2 CEN channel no sound
Problem
Solutions
1.2.3 Woofer channel no sound
Problem
Solutions
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CEN channel no sound
Broken or short circuit
Defective IC301 ,U901,IC502
C614,C618
Speaker cable dis-connect or
speaker damaged
Check solder points on
PCB
Check and Replace
defective IC or
Component
Re-connect speaker cable or
replace defective speaker(s)
Analyzer and
Identify the Causes
Woofer channel no sound
Broken or short circuit
Defective IC503,IC504,TC301
Q814,C614,C618
Speaker cable dis-connect or
speaker damaged
Check solder points on
PCB
Check and Replace
defective IC or
Component
Re-connect speaker cable or
replace defective speaker(s)
Analyzer and
Identify the Causes
Service Guide GHT-502D
1.2.4 Decoder no power
Problem
Solutions
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Decoder no power
Broken or short circuit
Defective D1-D4,IC1,C197
Speaker cable dis-connect or
speaker damaged
Check solder points on
PCB
Check and Replace
defective IC or
Component
Re-connect speaker cable or
replace defective speaker(s)
Analyzer and
Identify the Causes
Service Guide GHT-502D
Chapter 2. Specifications
Satellite - Center
(AT 1KHz)：
NO. Description Unit Specifications
1 Out Power at THD 10% W
7 ± 1
2 Sensitivity mV
1400 ± 300
3 Freq. Response (Ref:-3dB) Hz 28 ~ 9.5K
4 S/N ratio dB
≧ 70
5 Hum & Noise Vol: max mV
≦ 10
Satellite - Front(AT 1KHz)：
NO. Description Unit Specifications
1 Out Power at THD 10% W
7 ± 1
2 Sensitivity mV
670± 200
3 Freq. Response (Ref:-3dB) Hz 145 ~ 20K
4 Separation dB
≧ 40
5 S/N ratio dB
≧ 70
6 Hum & Noise Vol: max mV
≦ 10
Satellite - Rear(AT 1KHz)：
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NO. Description Unit Specifications
1 Out Power at THD 10% W
7 ± 1
2 Sensitivity mV
400± 100
3 Freq. Response (Ref:-3dB) Hz 170 ~ 15K
4 Separation dB
≧ 40
5 S/N ratio dB
≧ 70
6 Hum & Noise Vol: max mV
≦ 10
Service Guide GHT-502D
Host(Woofer)(AT 100Hz)：
NO. Description Unit Specifications
1 Out Power at THD 10% W
40 ± 5
2 Sensitivity mV
320± 100
3 Freq. Response (Ref:-3dB) Hz 20 ~ 150
4 S/N ratio dB
≧ 70
5 Hum & Noise Vol: max mV
≦ 10
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Service Guide GHT-502D
Chapter 3. Block Diagram
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RL/RR -AUDIO IN
Volume Control
&FILTER
Power
Amplifier
FL.CH Speaker
RL.CH Speaker
Woofer CH Speaker
AC IN Transformer
Stand-By
FR.CH Speaker
RR.CH Speaker
CEN.CH Speaker
Power
Amplifier
Power
Amplifier
FL/FR -AUDIO IN
SUB/CEN -AUDIO IN
Volume Control
&FILTER
Volume Control
&FILTER
Service Guide GHT-502D
Chapter 4. Exploded View
Host ( Woofer )
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Service Guide GHT-502D
Satellite
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Service Guide GHT-502D
Chapter 5. Part List
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No. DESCRIPTION Qty UNIT Part No.
1 GHT-502/BODY/SATELLITE-FL 1 PC 3-101-01
2 GHT-502/BODY/SATELLITE-FR 1 PC 3-101-02
3 GHT-502/BODY/SATELLITE-RL 1 PC 3-101-03
4 GHT-502/BODY/SATELLITE-RR 1 PC 3-101-04
5 GHT-502/BODY/SATELLITE-CEN 1 PC 3-101-05
6 SPEAKER UNIT DBA218 5 PC 2-100-01
7 RUBBER, SW-FLAT2.1 1250/SATE. 10 PC 2-100-07
8 GHT-502D/BODY/WOOFER/230V-EU 1 PC 4-101-01
9 SPEAKER UNIT 6.5” 4 ohm 40W 1 PC 3-100-01
10 PCBA, GHT-502D 1 PC 4-101-02
1 1 IC, TDA7377, SW-Flat2.1 1250 1 PC 2-100-06
12 IC, TDA2030A, GHT-502 3 PC 3-100-02
13 IC, YG4558/MC4558, SW-Flat2.1 1250 1 PC 2-100-04/05
14 IC, TL084N, GHT-502 1 PC 3-100-04
15 IC, L7812, GHT-502D 1 PC 4-100-01
16 RUBBER, SW-Flat2.1 1250/HOST 4 PC 2-100-08
17
TRANSFORMER, 230V:13.4VACx2 & 3.7A;
14.5VAC & 0.8A
1 PC 4-100-02
18 AUDIO CABLE-1, 3 to 3 , GHT-502 1 PC 3-100-08
19 DC POWER CORD, GHT-502D 1 PC 4-100-03
20 CARTON, GHT-502D 1 PC 4-102-03
21 CUSHION, GHT-502D 1 SET 4-102-02
22 Round Yellow Type Label ( ON CARTON ) 2 PC 1-102-05
23 S/N LABEL ( ON CARTON & WOOFER) 2 PC 4-102-01
24 MANUAL, GHT-502D 1 PC 4-102-04
25 PE BAG, SW-Flat2.1 1250/HOST 1 PC 2-102-07
Service Guide GHT-502D
26 PE BAG, SW-Flat2.1 1250/SATE. 5 PC 2-102-08
27 PE BAG, DC POWER CORD, GHT-502D 1 PC 4-102-05
28 PE BAG, AUDIO CABLE 1 PC 3-102-05
29 CARDBOARD, English, GHT-502D 1 PC 4-102-06
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Service Guide GHT-502D
Chapter 6. Schematic Diagram
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Service Guide GHT-502D
Chapter 7. Important Notes
7.1 Packing Requirement for Sending the PCB Assembly by Post
PCB assembly is a kind of sophisticated electronic circuit board. Well
packing will be required when sending them by post.
* Some sophisticated IC components are mounted on the PCB assembly,
hence it is necessary to pack each PCB assembly with a separate static
protecting bag, in order to avoid static electricity.
* Reliable external packing is also very important when sending PCB
assembly by post, in that it would avoid unnecessarily lost or damage.
7.2 Short of Spare Parts while Repairing a Speaker System
If you are short of spare parts when you have some speaker systems waiting
to be repaired, it would be recommended to take the necessary parts form
one speaker system, so that you may have the as many speaker systems.
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