XL-UH4H (serv.man2) - Sharp Audio Service Manual (repair manual)

XL-UH4H

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[1]  Safety Precaution For Service Manual ........1-1

[2]  Important Service Notes (For U.K. Only) .....1-2

[3]  Specifications...............................................1-2

[4]  Names Of Parts ...........................................1-3

[1]  Disassembly ................................................2-1

[1]  Block Diagram .............................................3-1

[1]  Waveforms Of Servo Circuit ........................4-1

[2]  Voltage.........................................................4-3

[1]  Notes On Schematic Diagram ..................5-1

[2]  Types Of Transistor And LED ................... 5-1

[3]  Wiring Side Of PWB/Schematic Diagram. 5-2

[1]  Troubleshooting ........................................6-1

[1]  Function Table Of IC.................................7-1

[2]  LCD Display............................................ 7-12

[3]  Wiring Of Primary Supply Leads

(For U.K. Only)........................................ 7-13

No. S7626XLUH4H//

Parts marked with "      " are important for maintaining the safety of the set. Be sure to replace these parts with

specified ones for maintaining the safety and performance of the set.

• Note for users in U.K.

Recording  and  playback  of  any  material  may  require

consent  which  SHARP  is  unable  to  give.  Please  refer

particularly  to  the  provisions  of  Copyright  Act  1956,  the

Dramatic and Musical Performers Protection Act 1956, the

Performers  Protection  Acts  1963  and  1972  and  to  any

subsequent statutory enactments and orders. 

• In the interests of user-safety (Required by safety regula-

tions in some countries) the set should be restored to its

original condition and only parts identical to those specified

be used.

This document has been published to be used for after

sales service only.

The contents are subject to change without notice.

XL-UH4H

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Example:

Indicates lead-free solder of tin, silver and copper.

Lead-free wire solder for servicing

PWB-A1

92LUH400280029

92LUH401280000

PWB-A3

AUDIO

PWB-A2

92LUH400380003

CONTROL

RECTIFIER

PWB-B

92LUH400980000

CD

PWB-C

92LUH403280000

MCU

PWB-D

92LUH403080000

USB

"AUDIO, CONTROL, RECTIFIER, CD, MCU, USB PWB" of this model employs lead-free solder.
The LF symbol indicates lead-free solder, and is attached on the PWB and service manuals. The alphabetical 
character following LF shows the type  of lead-free solder.

When fixing the PWB soldered with the lead-free solder, apply lead-free wire solder. Repairing with conventional 
lead wire solder may cause damage or accident due to cracks.
As the melting point of lead-free solder (Sn-Ag-Cu) is higher than the lead wire solder by 40 C, we recommend 
you to use a dedicated soldering bit, if you are not familiar with how to obtain lead-free wire solder or soldering 
bit, contact our service station or service branch in your area.

As the melting point of lead-free solder (Sn-Ag-Cu) is about 220 C which is higher than the conventional lead 
solder by 40 C,and as it has poor solder wettability, you may be apt to keep the soldering bit in contact with the 
PWB for extended period of time. However, since the land may be peeled of for the maximum heat-resistance 
temperature of parts may be exceeded, remove the bit from the PWB as soon as you confirm the steady 
soldering condition.
Lead-free solder contains more tin, and the end of the soldering bit may be easily corrected. Make sure to turn 
on and off the power of the bit as required. If a different type of solder stays on the tip of the soldering bit, it is 
alloyed with lead-free solder. Clean the bit after every use of it.
When the tip of the soldering bit is blackened during use, file it with steel wool or fine sand paper.
Be careful when replacing parts with polarity indication on the PWB silk.

i

XL-UH4H

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Laser Diode Properties
Material: AIGaAs
Wavelength: 790 nm
Emission Duration: continuous
Laser Output: max. 0.6 mW

Laser Diode Properties
Material: AIGaAs
Wavelength: 790 nm
Emission Duration: continuous
Laser Output: max. 0.6 mW

This product is classified as a CLASS 1 LASER PRODUCT.

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XL-UH4H

1 – 4

Before returning the unit to the customer after completion of a repair or
adjustment it is necessary for the following withstand voltage test to be
applied to ensure the unit is safe for the customer to use.

Setting of Withstanding Voltage Tester and set.

Set name

set value

Withstanding Voltage Tester
Test voltage

4,240 VPEAK
3,000 VRMS

Set time

6 secs

Set current (Cutoff current)

4 mA

Unit
Judgment
OK: The “GOOD” lamp lights.
NG: The “NG” lamp lights and the buzzer sounds.

PROBE

AC

OUT

UNIT

SHORT-CIRCUIT
AC POWER
SUPPLY CORD

CONNECT THE PROBE
TO GND OF CHASSIS
SCREW

WITHSTANDING

VOLTAGE TESTER

FOR A COMPLETE DESCRIPTION OF THE OPERATION OF THIS UNIT, PLEASE REFER TO THE OPERATION MANUAL.

AC 230 V, 50 Hz

Power on: 26 W
Power stand-by: 0.6 W(*)

Width: 144 mm (5-11/16")
Height: 210 mm (8-5/16")
Depth: 239 mm (9-7/16")

2.3 kg (5.1 lbs.)

( * )This power consumption value is obtained when the unit is in the

power stand-by mode.

PMPO: 160 W
MPO: 30 W (15 W + 15 W) (DIN 45 324)
RMS: 16 W (8 W + 8 W) (DIN 45 324)
RMS: 12 W (6 W + 6 W) (DIN 45 500)

Speakers: 4 ohms

Headphones: 16 - 50 ohms
(recommended: 32 ohms)

Compact disc player

Non-contact, 3-beam semi conductor laser
pickup

1-bit D/A converter

20 - 20,000Hz

90 dB (1kHz)

FM: 87.5 - 108MHz

AM: 522 - 1,620kHz

Mass storage class

MP3/WMA (do not support DRM file)

FAT 16 or FAT 32

MP3 (32 ~ 320 kbps)
WMA (64 ~ 160 kbps)

MP3 ID3 - tag only supports version 1.x
USB supports version 2.0

2-way type speaker system
5 cm (2") tweeter
10 cm (4") woofer

8 W

4 ohms

Width: 135 mm (5-5/16")
Height: 242 mm (9-1/2")
Depth: 205 mm (8-1/16")

1.8 kg (4 lbs.)/each

16 W

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