28JW-73H (serv.man30). Additional Beam Current Sensing Circuit — Sharp TV Technical Bulletin (repair manual)

Model
28JW-73H (serv.man30)
Pages
3 Few pages! See other manuals at the bottom of the first or last page.
Size
91.52 KB
Type
PDF
Document
Technical Bulletin
Brand
Device
TV / CTR / Additional Beam Current Sensing Circuit
File
28jw-73h-sm30.pdf
Date

View Sharp 28JW-73H (serv.man30) Technical Bulletin online

CTV2004 06 04 
 
Date of Issue:   
8
th
 July 2004 
         
Classification:  
White 
TELEVISION TECHNICAL BULLETIN
 
Page 1 of 3 
 
 
Sharp Electronics (UK) Limited 
Reference – JC 16 06 2004
 
Revision  - 2 
 
White – Carry out as required 
Yellow – Carry out as required and whenever the unit comes in for service 
 Red – Carry out on all units   
 
MODELS 28JW73H  28JF73H 
32JW73H   
 
 
 
REASON
 
To improve the beam current protection reaction time, extra components have been 
added to the circuit.   This circuit is physically located underneath the line output 
transformer (T601).   
 
These changes have taken place from the following serial numbers 
 
 
28JW73H 
310 
872260 
    
32JW73H 310 
518287 
 28JF73H 
310 
525170 
 
 
ACTION 
For models that have serial numbers higher than those given above, please note the 
circuit changes outlined in this Technical Bulletin. 
 
Notes 
x D1307 was originally a 5.2V zener diode, but it was found that this made the circuit 
too sensitive to beam current variations and the set would turn off to standby either 
on channel change or dark to bright scenes.  To alleviate this it was changed to a 
6.1V zener diode. 
x
It is advisable to change D1307 to a 6.1V zener diode (if not already carried out) to 
prevent phosphor burn.
 
 
 
REF NO DESCRIPTION PART 
NUMBER PRICE 
CODE 
D1307 Zener 
Diode 
6.1V 
RH-EX0584BMZZ 
AA 
C1336 
Capacitor, 1
PF 50V 
VCEA0A1HW105M AA 
IC1303 IC, 
UPC358G2 
VHIUPC358G/-1 
AE 
J0018 
Jumper Wire, 300mm 
VW7UGB1-300KK 
AA 
J0019 
Jumper Wire, 200mm 
VW7UGB1-200KK 
AA 
Q1306 SMD 
Transistor, 
2SC3198 
VS2SC3198-G-1 
AA 
R1323 
SMD Resistor, 1M
VRS-CY1JF105G AA 
R1324 
SMD Resistor, 56k
VRS-CY1JF563G AA 
R1325 
SMD Resistor, 1.8M
VRS-CYJF185G AA 
R1326 
SMD Resistor, 2.2k
VRS-CYJF222J AA 
R1327 
SMD Resistor, 1k
VRS-CYJF102J AA 
R1328 
SMD Resistor, 56k
VRS-CYJF563J AA 
R1329 
SMD Resistor, 2.2k
VRS-CY1JF222J AA 
 
CTV2004 06 04 
 
Date of Issue:   
8
th
 July 2004 
         
Classification:  
White 
TELEVISION TECHNICAL BULLETIN
 
Page 2 of 3 
 
 
Sharp Electronics (UK) Limited 
Reference – SP035101X
 
Revision  - 1 
 
White – Carry out as required 
Yellow – Carry out as required and whenever the unit comes in for service 
 Red – Carry out on all units   
 
Schematic Diagram of the New Circuit 
 
 
 
 
Loction of Components - Print Side of the PWB 
 
CTV2004 06 04 
 
Date of Issue:   
8
th
 July 2004 
         
Classification:  
White 
TELEVISION TECHNICAL BULLETIN
 
Page 3 of 3 
 
 
Sharp Electronics (UK) Limited 
Reference – SP035101X
 
Revision  - 1 
 
White – Carry out as required 
Yellow – Carry out as required and whenever the unit comes in for service 
 Red – Carry out on all units   
 
 
 
 
Loction of Components - Component Side of the PWB 
 
 
 
 
 
Page of 3
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Download Sharp 28JW-73H (serv.man30) Technical Bulletin

Here you can view online or download Sharp 28JW-73H (serv.man30) Technical Bulletin in pdf. This Technical Bulletin can help you recover, restore, fix, disassemble and repair Sharp 28JW-73H (serv.man30) CTR. Information contained in Sharp 28JW-73H (serv.man30) service manual (repair manual) typically includes:

  • Disassembly, troubleshooting, programming, maintenance, remote, adjustment, installation and setup instructions.
  • Schematics, wiring and block diagrams.
  • Printed wiring boards (PWB) and printed circuit boards (PCB).
  • Parts list (bill of materials).