Genius SP-HF1255A User manual

Service Guide SP-HF1255A
1
SERVICE GUIDE
KEY SYSTEM CORP

Service Guide SP-HF1255A
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Revision History
Version Date Change
1.0 2009-12-22

Service Guide SP-HF1255A
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Table of Contents
Revision History………………………………………………………………….2
Table of contents……………………………………………………………....…3
Getting Start…………………………………………………….………………..4
Conventions Used in this Guide…………………………………………….…...4
Safety Precautions………………………………………………………….……4
Chapter 1. How to Handle Defective Returns………………………………..….5
1.2 Problem………………………………………………………………………6
1.2.1 No power，LED （indicator）unlighted………………………………...7
1.2.2 No sound…………………………………………………………….…….8
1.2.3 Right or left channel no sound….……….……….……….……..….…...…9
1.2.4 Noise………………………………….…………………………....…..…10
1.2.5 LED indicators no light…………………………….….……………...….11
1.2.6 Headphone jack output no sound……………………………..……...…..12
1.2.7 VR, headphone jack or line-in jack abnormal……..………….…...……..13
Chapter 2. Specification……………………………………………….….……14
Satellite……………………………………………………..…………….……14
Chapter 3. Block diagram…………………………………………..……...…..15
Chapter 4. Part list…………………………………… …………….………….16
Chapter 5 Important notes……………………………………………………...17
Chapter 6. Exploded view………………………………………………...……18
Right Satellite…………………………………………………..…….…...……18
Left Satellite…………………………………………………………………….19
Chapter 7 Schematic diagram……………………………………..…….………20

Service Guide SP-HF1255A
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Getting Started
Conventions Used in the 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 handing 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.
Do not perform any maintenance with wet hand.
Prevent foreign substance, such as water, other liquids or chemical, from entering the speakers while
performing maintenance procedures on the speakers.

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Chapter 1 How to Handle Defective Returns
1.1 Overview
Receiving Defective speaker from customers
FUNCTION NG
FUNCTION NG FUNCTION OK
FUNCTION OK
Verifying problems
proceeding necessary
tests
Analyzing possible, Main function cause
Deciding & Proceeding the Rectification
methods
Replace Necessary defective parts
Verifying problems
Proceeding Necessary
tests
Return the speakers with proper repacking to
customers

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1.2 Problems
Item ItemProblemDescription
1.2.1 No power，LED （indicator）no light
1.2.2 No sound
1.2.3 Right or left channel no sound
1.2.4 Noise
1.2.5 LED indicator no light
1.2.6 Headphone jack output no sound
1.2.7 VR, headphone jack or line-in jack abnormal

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Attention
1.2.1 No power, LED (indicator) unlighted
Problem
Analyze
and
identify
the
causes
Solutions
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.
Defective transformer
Defective or damaged AC
cable or power switch
Or caused by the following:
1. Transformer secondary wire loosely
connected with 1CN1 jack in
SP-HF1255AAMPA.
2. Copper foil of SP-HF1255A AMP
PCBA broken
Repair or replace Re-solder or replace
No power，LED （indicator）unlighted

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1.2.2 No Sound
Problem
Analyze
and identify
thecauses
Solutions
No Sound
PCB
short-circuited,
dry soldered or
broken
CN1 and CN2 in
AMP board is not
properly connected
Or caused by the
following defective
components
1. U1, U2 in AMP
PCBA
2. VR1，N2，1CN4 in
SP-HF1255A AMP
PCBA
Repair or
Replace
Repair or
Replace
Repair,
re-solder or
Replace

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1.2.3 Right or left channel no sound
Problem
Analyze
and identify
thecauses
Solutions
Right or left channel no sound
PCB damaged,
dry-soldered or
short-circuited;
CN1 in
SP-HF1255A
and CN2 in
SP-HF1255A
AMP PCBA
are loosely
connected
Driver unit or speaker
cable defective or
loosely connected
Audio cable defective
or loosely connected
VR ，N2 or 1CN4
defective in
SP-HF1255A AMP
PCBA
Repair or
Replace
Repair or
Replace
Re-connect,
replace or
repaire

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1.2.4 Noise
Problem
Analyze
and identify
thecauses
Solutions
Noise
Filter capacitor
/diode
dry-soldered or
damaged,
please check
C1, C14, C31，
C20，C9, 1D1，
1D2,1D3, 1D4
in AMP
defective or
not;
The power
supply of each
IC is normal or
not
Or caused by
vibration from too
long lead wire of
driver units
Driver units damaged
Woofer cabinet leaks,
closed not well
Repair
Check and
replace
Repair or
replace

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1.2.5 LED indicator no light
Problem
Analyze
and identify
thecauses
Solutions
LED indicator no light
1. PCB damaged, dry-soldered or short-circuited
2. R3 in SP-HF1255AAMP PCB defective
3. Poor connection of 1CN1 in SP-HF1255A PCB and
power switch in rear panel
4. Defective LED1 in SP-HF1255AAMP PCB
Check and replace

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1.2.6 Headphone jack output no sound
Problem
Analyze
and identify
thecauses
Solutions
Headphone jack no sound
N1 in 1255A AMP PCBA defective or its related copper
foil broken
Check and replace

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1.2.7 VR, headphone jack or line-in jack abnormal
Problem
Analyze
and identify
thecauses
Solutions
VR, headphone jack or line-in jack abnormal
VR:
Defective VR may cause VR3
in
1255A AMP PCB or
VR1/VR2 in
SP-HF1255A AMP PCBA
having
scratching sound when rotatin
Check and replace
Jack:
N1 or 1CN4 in 1255A AMP
PCBA
defective
Check and replace

Service Guide SP-HF1255A
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Chapter 2 Specifications
Satellite
Normal
No Description Unit R L Limit
1 RATED OUTPUT POWER @THD 10% W 23.5 22.6 ≧20
2 SENSITIVITY (1KHz) @RATED O/P
POWER m V 613 640 600±60
3 SENSITIVITY (1KHz)
@1W O/P POWER m V 260 260 260±60
4 MAX INPUT LEVEL
@1% THD m V 370 380 370±35
5 DISTOPTION@1kHz 1W OUT % 0.8 0.8 ≦1
6 FREQUENCY RESPONSE
(1KHz -3DB ) LOW Hz 20 20 20±10
7 FREQUENCY RESPONSE
(1KHz -3DB ) HI KHz 20 20 20±5
8 S/N@RATED O/P POWER d B 75 75 ≧70
9 CHANNEL UNBALANCE
@REF O/P POWER d B 0.3 0.5 ≦1
10
CHANNEL SEPARATION
(ONE CHANNELIN;OTHER
CHANNEL INPUT SHORTING
d B 51 51 ≧40
11 HUM NOISE (VOLUME MAX;INPUT
SHORTING) m V 1.6 1.6 ≦2
12 HUM NOISE (VOLUME MIN INPUT
SHORTING) m V 0.3 0.4 ≦1
Woofer
No Description Unit Normal Limit
1 RATED OUTPUT POWER@100HZ (10%THD) W
2 SENSITIVITY (100Hz) @RATED O/P POWER m V
3 SENSITIVITY (100Hz) @1W O/P POWER m V
4 MAX INPUT LEVEL@1% THD m V
5 DISTOPTION@100Hz 1W OUT %
6 FREQUENCY RESPONSE(100Hz -3DB ) LOW Hz
7 FREQUENCY RESPONSE(100Hz -3DB ) HI Hz
8 S/N RATIO@100HZ RATED O/P POWER d B
9 HUM NOISE (VOLUME MAX;INPUT SHORTING) m V
10 HUM NOISE (VOLUME MIN INPUT SHORTING) m V

Service Guide SP-HF1255A
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Chapter 3 Block diagram
AUX LINE IN
T
R
E
B
A
S
V
O
L
POWER
4588
FILTER
HEADPHONE
JACK
STA540SA
POWER AMP
R
SPEAKER
L
SPEAKER

Service Guide SP-HF1255A
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Charter 4 Part List
Right
Description Part No.
wooden cabinet, SP-HF1255A 21.6.020.0033
driver unit, (woofer/tweeter) 21.8.040.0031
21.8.920.0008
AMP PCBA, SP-HF1255A 21.1.003.0121
knob 21.4.014.0063
power switch 11.1.192.0003
transformer, 230V 50HZ/14V-2.5A 11.2.001.0090
woofer driver unit cloth cover, SP-HF1255A 11.6.005.0052
U1， STA540SA 11.1.170.0122
U2, 4558 11.1.170.0056
AC cable 11.3.001.0035
VR1/VR2, 16KG-B50K-L15 MID POSITIONING 11.1.030.0028
VR3, 16KG-B50K-L15 11.1.030.0009
Left
Description Part No.
Wooder driver unit cloth cpver 11.6.005.0052
driver unit, (woofer/tweeter) 21.8.040.0031
21.8.920.0008
Wooden cabinet,SP-HF1255A satellite 21.6.030.0048
Decorative ring 21.4.019.0061
21.4.019.0060

Service Guide SP-HF1255A
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Chart 5 Important notes
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 the PCB assembly by post, in that it
would avoid unnecessarily lost or damage
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 from one
Speaker system, so that you may have them as many speaker systems

Service Guide SP-HF1255A
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Chapter 6 Exploded view
Right

Service Guide SP-HF1255A
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Chapter 6 Exploded view
Left

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Chapter 7 Schematic diagram