DOWNLOAD Sharp 28JF-73H (serv.man21) Service Manual ↓ Size: 6.09 MB | Pages: 64 in PDF or view online for FREE

Model
28JF-73H (serv.man21)
Pages
64
Size
6.09 MB
Type
PDF
Document
Service Manual
Brand
Device
TV / CTR
File
28jf-73h-sm21.pdf
Date

Sharp 28JF-73H (serv.man21) Service Manual ▷ View online

1
28JF-73H
      MODEL 
28JF-73H
 PAL I SYSTEM COLOUR TELEVISION
SE
00
28JF73H00
SERVICE MANUAL
                Issued: 29
th
 July  2002
  GA-20
 CHASSIS
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.
CONTENTS
ELECTRICAL SPECIFICATIONS ................... 3
IMPORTANT SERVICING NOTES ................. 4
CONTROLS & TERMINALS ........................... 5
ADJUSTMENT PROCEDURES ...................... 7
POSTCODE RESET ...................................... 11
LED FLASHING CODES ............................... 12
PRINTED WIRING BOARDS ........................ 13
CHASSIS LAYOUT ......................................... 20
ICs ADDITIONAL INFORMATION .................. 22
SCHEMATIC DIAGRAMS ............................... 37
TROUBLESHOOTING TABLES ..................... 51
PARTS LISTING ............................................. 54
SOURCE OF DOCUMENTATION .................. 62
PACKING OF THE SET & ACCESSORIES ... 63
SHARP  CORPORATION
2
28JF-73H
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.
3
28JF-73H
ELECTRICAL SPECIFICATIONS
•Focus ....................... High Bi-Potential Electrostatic
•Sweep Deflection ..................................... Magnetic
•Picture Intermediate frequency................... 38.9MHz
•Sound  Carrier Trap................................... 32.9MHz
•Adjacent  Sound Carrier Trap ................... 40.9MHz
•Adjacent  Picture  Carrier Trap.................. 30.9MHz
.
•Aerial Input Impedance
VHF/UHF ...................... 75 ohm Unbalanced
•Tuning Ranges........... 45.75 MHz thru 855.25 MHz
VHF: IR A - J / S1 - S41 CH (Hiperband)
UHF: I21 - I69 CH
•White Level
Set brightness control to get total picture tube cathode current of 600 
µA under no signal condition.
Maximum necessary correction of each picture tube cathode current to get 8900 degrees
 
K-20 MPCD
screen temperature should not exceed 15% of its original value.
X=0.290 ± 0.015         Y=0.284 ± 0.015
                                            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.
•Power Input .................... 220V-240 Volts AC 50Hz
•Power Consumption
Normal Operation (Method IEC60107) ............ 77W
Stand-by Operation ............................................ 3W
•Audio Power Output Rating (MPO) / Impedance
Internal Left Speaker ................................. 10W, 7
Internal Right Speaker .............................. 10W, 7
•Speakers
Left / Right ................................................. 12 x 6cm
•Convergence (Maximum Misconvergence)
Static (Centre) between any two  colours  ... 0.08 cm
Dynamic after static equals zero
Within 10cm (4”) circle ....................... 0.12cm
10-25cm (4-10” ) circle ...................... 0.20 cm
Everywhere else ................................ 0.28 cm
4
28JF-73H
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 disconnected 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:
1. When undertaking any servicing on this chassis, DO NOT increase the EHT  to more than 32.5 KV, (at a
instantaneous beam current of 1500
µA
)
.
2. Ensure that during normal operation the EHT does not exceed 30.0 KV±1.5KV (at a beam current of
1700
µA). This level has been preset in the factory. Always check that this level has not been exceeded
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.
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.
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.
Page of 64
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Sharp 28JF-73H (serv.man21) Service Manual ▷ Download

  • DOWNLOAD Sharp 28JF-73H (serv.man21) Service Manual ↓ Size: 6.09 MB | Pages: 64 in PDF or view online for FREE
  • Here you can View online or download the Service Manual for the Sharp 28JF-73H (serv.man21) in PDF for free, which will help you to disassemble, recover, fix and repair Sharp 28JF-73H (serv.man21) CTR. Information contained in Sharp 28JF-73H (serv.man21) Service Manual (repair manual) includes:
  • Disassembly, troubleshooting, maintenance, adjustment, installation and setup instructions.
  • Schematics, Circuit, Wiring and Block diagrams.
  • Printed wiring boards (PWB) and printed circuit boards (PCB).
  • Exploded View and Parts List.