Sharp 21HS-50H User manual

1
21HS-50H
MODEL 21HS-50H
GA-1E CHASSIS
Issued: 24th October 2001
SERVICE MANUAL
SHARP CORPORATION
PAL I SYSTEM COLOUR TELEVISION
SEBD21HS50H01
In the interests of user safety (required by safety
regulationsinsomecountries)thesetshouldrestored
to its original condition and only parts identical to
those specified should be used.
This document has been published to
be used for after sales service only.
ELECTRICALSPECIFICATION.........................3
IMPORTANT SERVICING NOTES ...................4
CONTROLS& TERMINALS..............................5
SERVICEADJUSTMENTS................................6
CHASSISLAYOUT...........................................12
LEDFLASHING CODE....................................13
PRINTED WIRING BOARDS...........................13
ICs ADDITIONAL INFORMATION...................18
SCHEMATIC DIAGRAM, WAVE FORMS........26
BLOCKDIAGRAM...........................................32
TROUBLESHOOTINGTABLES......................34
PARTS LISTING.............................................37
CONTENTS

2
21HS-50H
Use this page to keep any special servicing information as Technical Report (Bulletin), Technical Information, etc.
If only part number changes are required, just change part number directly the part number in the Parts Listing Section.
If you need more information, please refer to the Technical Report (Bulletin).
SERVICE MANUAL UPDATE LOG SHEET
Part No.
Technical Report No.
Technical Bulletin No. Cause / Solution Page No. Application
Data /Serial No.

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21HS-50H
ELECTRICAL SPECIFICATIONS
•Power Input .......................220V-240 Volts AC 50Hz
•Power Consumption
•Audio Power Output Rating ................4W x 2(MPO)
Speaker................................16Ω4W, 9 x 5 cm,2pcs
Normal Operation....................................43W
Stand-by Operation...................................3W
•White Level
Set the brightness control, with no signal connected, so that the CRT cathode current is 600mA. The maximum
correction applied to each cathode current to achieve a screen temperature of 8900 degrees K-20 MPCD should
not exceed 15% of its original value.
Convergence.........................Self Converging System
Focus....................................Bi-Potencial Electrostatic
Sweep Deflection...........................................Magnetic
•Aerial Input Impedance
VHF/UHF..........................75 ohm Unbalanced
•Tuning Ranges ............45.75MHz thru 855.25 MHz
VHF.............IR A - J
S1-S41 (HYPERBAND)
UHF.............I21 - I69 CH
•Picture Intermediate Frecuency..............38.9MHz
•Sound Carrier Trap...............................32.9MHz
•Adjacent Sound Carrier Trap.................40.9MHz
•Adjacent Picture Carrier Trap...............30.9MHz
WARNING
The chassis in this receiver is partially hot. Use an isolation transformer between the line cord plug
and power receptacle, when servicing this chassis.
To prevent electric shock, do not remove cover. No user-serviceable parts inside. Refer servicing to
qualified service personnel.
Specifications are subject to change without prior notice.
X Y Screen temperature
0.290±0.015 0.284±0.015 8900º K-20 MPCD

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21HS-50H
IMPORTANT SERVICING NOTES
Only qualified service personnel are allowed to carry out maintenance and repair of this receiver.
SERVICING OF HIGH VOLTAGE SYSTEM AND CRT
It is important that the static charge is removed from the high voltage system when carrying out work
onthereceiver.Thiscanbeachievedbyconnectinga10Kresistor(withasuitablyinsulatedlead)from
theCRT cavityconnectortotheCRTgroundtag.Thismustbecarriedoutwiththe AC supply discon-
nected from the receiver.
Note the following:
•The CRT in this receiver employs Integral Implosion Protection.
•If the CRT has to be changed it MUST be replaced with the correct type for continued safe
working
•DO NOT lift the CRT by its neck.
•When handing the CRT, ensure that shatterproof goggles are worn.
•Ensure that the CRT is discharge before handling.
X-RAY
This receiver is designed to keep any x-ray emission to an absolute minimum. Some fault conditions
andservicing proceduresmay producepotentiallyhazardous x-rayradiation levels.This is a problem
when in close proximity to the receiver for long periods of time. Toreduce any risks associated with
this, please observe the following precautions:
1.Whenundertakinganyservicingonthischassis,DONOTincreasetheEHT tomore than 30.5 KV,
(at a instantaneous beam current of 1300µΑ).
2.EnsurethatduringnormaloperationtheEHTdoesnotexceed25.0KV±1.5KV(atabeamcurrentof
1100µΑ). This level has been preset in the factory. Always check that this level has not been ex-
ceeded after carrying out any repair on the receiver.
3. DO NOT replacethe CRT with any other type than that specified in the parts listing as this may
cause excessive x-ray radiation.
BEFORE RETURNING THE RECEIVER TO THE CUSTOMER
Inadditiontothe above checks,thefollowingshould also becarriedout before returning the receiver
to the customer.
1. Inspect all the leads to ensure that they are dressed correctly and that they are not obstructed or
pinched by any other parts.
2. Ensure that all protective devices are in good condition. These will include nonmetallic control
knobs,insulatingfishpapers,cabinetsbacks,compartmentcovers or shields, mechanical insulators,
etc.

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21HS-50H
MENU CH
Power ( ) button
Power/On Timer indicator
Remote Control Sensor
Menu button
Volume U ( )/Down ( ) buttons
Channel U ( )/Down ( ) buttons
TV/VIDEO
VCRTV
CH
CH
MENU
LIST
GA006SA
TV/ VCR/ TEXT REMOTE CONTROL
123
456
78
0
9
TV
VCR
CH
CALL ( )/CHILD LOCK ( ) button
Infr red Tr nsmitter Window
Aim this window at the infrared sensor
on yourTV set
FLASHBACK ( ) button
Returns to previously viewed
programme
TV/VIDEO Select button
POWER/STANDBY ( ) button
Progr mme Select buttons
MENU button
HALF PAGE ( ) button (Teletext)
VOLUME UP ( )/DOWN ( ) buttons
( ) Increases sound
( ) Decreases sound
(These are also used for menu set up)
CANCEL ( ) button (Teletext)
RESET ( ) button (Teletext)
Single/Double Entry button ( )
Text/Mix ( )
Select button (Teletext)
COLOUR buttons
REVEAL ( ) button (Teletext)
TV button (Teletext)
HOLD ( ) button (Teletext)
CHANNEL (PROGRAMME) UP ( )/
DOWN ( ) buttons
( ) Selects next higher programme
( ) Selects next lower programme
(These are also used for menu
set up)
STORE ( ) button (Teletext)
SOUND MUTE ( ) button
CLOCK ( ) button (Teletext)
Sound Mode Select ( ) button
INDEX ( ) button (Teletext)
LIST Select button (Teletext)
26
Location of Controls
Remote Control
TV Front
Euro-SCART 21-Pin Terminal
1. Audio right output
2. Audio right input
3. Audio left output
4. Common earth for audio
5. Earth for blue
6. Audio left input
7. Blue input
8. Audio-video control
9. Earth for green
10. Not used
11. Green input
12. Not used
13. Earth for red
14. Not used Audio: Stereo Input / Output.
21-Pin Euro-
15. Red input
16. Red/Green/Blue
control
17. Earth for video
For greater A/V enjoyment, various audio and video devices may be
connected via the Euro-SCART 21-Pin Terminal.
18. Earth for video
19. VIDEO output
20. VIDEO input
21. Common earth