Read Sharp 21HS-50 (serv.man8) Service Manual online
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
regulations in some countries) the set should restored
to its original condition and only parts identical to
those specified should be used.
regulations in some countries) the set should restored
to its original condition and only parts identical to
those specified should be used.
ELECTRICAL SPECIFICATION.........................3
IMPORTANT SERVICING NOTES ...................4
CONTROLS & TERMINALS..............................5
SERVICE ADJUSTMENTS................................6
CHASSIS LAYOUT...........................................12
LED FLASHING CODE....................................13
IMPORTANT SERVICING NOTES ...................4
CONTROLS & TERMINALS..............................5
SERVICE ADJUSTMENTS................................6
CHASSIS LAYOUT...........................................12
LED FLASHING CODE....................................13
PRINTED WIRING BOARDS...........................13
ICs ADDITIONAL INFORMATION...................18
SCHEMATIC DIAGRAM, WAVE FORMS........26
BLOCK DIAGRAM...........................................32
TROUBLESHOOTING TABLES......................34
PARTS LISTING.............................................37
ICs ADDITIONAL INFORMATION...................18
SCHEMATIC DIAGRAM, WAVE FORMS........26
BLOCK DIAGRAM...........................................32
TROUBLESHOOTING TABLES......................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).
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.
Technical Bulletin No.
Cause / Solution
Page No.
Application
Data /Serial No.
Data /Serial No.
3
21HS-50H
ELECTRICAL SPECIFICATIONS
•
Power Input .......................220V-240 Volts AC 50Hz
•
Power Consumption
•
Audio Power Output Rating ................4W x 2(MPO)
Speaker................................16
Ω
4W, 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.
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
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.
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
4
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
on the receiver. This can be achieved by connecting a 10K resistor (with a suitably insulated lead) from
the CRT cavity connector to the CRT ground tag. This must be carried out with the AC supply discon-
nected from the receiver.
Note the following:
on the receiver. This can be achieved by connecting a 10K resistor (with a suitably insulated lead) from
the CRT cavity connector to the CRT ground tag. This must be carried out with the 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
and servicing procedures may produce potentially hazardous x-ray radiation levels. This is a problem
when in close proximity to the receiver for long periods of time. To reduce any risks associated with
this, please observe the following precautions:
and servicing procedures may produce potentially hazardous x-ray radiation levels. This is a problem
when in close proximity to the receiver for long periods of time. To reduce any risks associated with
this, please observe the following precautions:
1. When undertaking any servicing on this chassis, DO NOT increase the EHT to more than 30.5 KV,
(at a instantaneous beam current of 1300
(at a instantaneous beam current of 1300
µΑ).
2. Ensure that during normal operation the EHT does not exceed 25.0 KV
±
1.5KV (at a beam current of
1100
µΑ).
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 replace the CRT with any other type than that specified in the parts listing as this may
cause excessive x-ray radiation.
cause excessive x-ray radiation.
BEFORE RETURNING THE RECEIVER TO THE CUSTOMER
In addition to the above checks, the following should also be carried out before returning the receiver
to the customer.
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, insulating fish papers, cabinets backs, compartment covers or shields, mechanical insulators,
etc.
pinched by any other parts.
2. Ensure that all protective devices are in good condition. These will include nonmetallic control
knobs, insulating fish papers, cabinets backs, compartment covers or shields, mechanical insulators,
etc.
