DOWNLOAD Sharp 28HW-53 (serv.man9) Service Manual ↓ Size: 4.65 MB | Pages: 44 in PDF or view online for FREE

Model
28HW-53 (serv.man9)
Pages
44
Size
4.65 MB
Type
PDF
Document
Service Manual
Brand
Device
TV / CTR
File
28hw-53-sm9.pdf
Date

Sharp 28HW-53 (serv.man9) Service Manual ▷ View online

4
28HW-53H
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:
 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 KV,
   (at a instantaneous beam current of 1500
µΑ).
2. Ensure that during normal operation the EHT does not exceed 30KV
±
1.5KV (at a beam current of
1300
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.
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.
5
28HW-53H
ADJUSTMENT PROCEDURES
All adjustments to this chassis, except for focus, are carried out in the service mode.
••••• SERVICE MODE
The service mode is provided to enable the engineer to correctly set up the receiver to the CRT fitted in the set.
Note that these adjustments may vary from one receiver to another.
To enter the service mode, carry out the following procedure.
1. Connect a test pattern to the antenna terminal.
2. Tune the receiver to this signal.
3. Turn the receiver off using the mains switch.
4. Press volume down and channel up buttons on the
    front of the receiver at the same time.
5. Keeping these buttons pressed, turn the mains on.
6. When the set starts up it will be in service mode.
7. Release the two buttons.
••••• Use the channel up and down buttons to move between the options.
••••• Use the volume control buttons to change the data.
••••• To store the data, use the stand-by button on the remote control.
••••• To exit the service mode, turn the receiver off using the mains switch.
When the service mode is entered the following On Screen Display appears
-SERVICE SOFTWARE AND HEXADECIMAL COUNTER DISPLAY:
SW ON  XXXX   SW OFF  XXXX   HOURS ON  XXXX
The figures displayed in the XXXX locations are hexadecimal representations of the number of times that particular
function has been executed. For example if the hexadecimal number displayed after SW ON was 0E4A, this would
correspond to the receiver being turned on 3658 times.
Adjustment menu:
The following adjustments can be carried out in the service mode.
• Horizontal Shift
• East West Width
• Pin Phase
• Pin Amp
• Corner Amplitude
• Corner Symmetry
• Vertical Linearity
• Vertical Angle
• Vertical Bow
• Vertical Amplitude
• S Correction
• Vertical Shift
• Red Gain
• Green Gain
• Blue Gain
• Red Cut Off
• Green Cut Off
• Blue Cut Off
• Alter NVM Page
• Alter NVM Position
• Alter NVM Value
• Teletext Mix Mode Contrast
• Teletext Contrast
• OSD Contrast
• DVCO Adjustment (Only PAL)
• DVCO Adjustment (Only NTSC)
• AGC Adjustment
• AFT Adjustment
• OPC Value
• Auto Installation On/Off
Geometry Adjustments
All geometry adjustments are based on an internally generated test pattern as shown
in figure 1. When carrying out any of the above geometry adjustments, use the inter-
nally generated test pattern for guidance.
Fig.1
CH
4
5
6
28HW-53H
Note that the receiver should be set to FULL MODE before carrying out any geometry adjustments. This can be
achieved by pressing the widescreen mode button on the remote control until FULL MODE appears on the OSD.  This
can only be done out of the service mode.
The following geometry adjustments can be carried out.  Detailed instructions on how to execute these are given on
the following pages
 Horizontal
• Horizontal Shift
• E-W Width
• Pin Phase
• Pin Amp
• Corner Amplitude
• Corner Symmetry
Vertical
• Vertical Amplitude
• Vertical Shift
• Vertical Bow
• Vertical Angle
• S Correction
• Vertical Linearity
Just in case the the TV set requires a full geometries adjustment, please proceed  first with
Vertical according to the above order, and after that,  adjust Horizantal according to the
above  order.
Horizontal Shift
Adjust the horizontal shift so that the picture is centred.
The effect of this adjustment is shown in figure 2.
• When the volume up button is pressed, the picture moves to the right.
• When the volume down button is pressed, the picture moves to the left.
• Press the stand-by button on the remote control to store.
E-W Width
Adjust the E-W Width so that 9% over-scan is achieved.
The effect of this adjustment is shown in figure 3.
• When the volume up button is pressed, horizontal scanning increases.
• When the volume down button is pressed, horizontal scanning decreases.
• Press the stand-by button on the remote control to store.
Pin Phase
Adjust the Pin Phase so that the picture is symmetrical top and bottom.
The effect of this adjustment is shown in figure 4.
• When the volume up button is pressed, side pincushion changes.
• When the volume down button is pressed, side pincushion changes.
• Press the stand-by button on the remote control to store.
Pin Amp
Adjust the Pin Amplitude so that the picture is centred.
The effect of this adjustment is shown in figure 5.
• When the volume up button is pressed, side pincushion changes from pincushion to
barrel shape.
• When the volume down button is pressed, side pincushion changes from pincush-
ion to barrel shape.
• Press the stand-by button on the remote control to store.
Corner Amplitude
Adjust the Corner Amplitude so that the picture is centred.
The effect of this adjustment is shown in figure 6.
Note: This adjustment affects to upper and lower sides.
• When the volume up button is pressed, side pincushion changes from pincushion to
Fig.2
Fig.3
Fig.4
Fig.5
Fig.6
7
28HW-53H
barrel shape.
• When the volume down button is pressed, side pincushion changes from pincushion to
barrel shape.
• Press the stand-by button on the remote control to store.
Corner Symmetry
Adjust the Corner Symmetry so that the picture is centred.
The effect of this adjustment is shown in figure 7.
Note: This adjustment affects to upper and lower sides.
•  When the volume up button is pressed, side pincushion changes from pincushion to
barrel shape.
• When the volume down button is pressed, side pincushion changes from pincushion to
barrel shape.
• Press the stand-by button on the remote control to store.
Vertical Linearity
Adjust the Vertical Linearity so that the upper and lower parts of the picture are symmetrical.
The effect of this adjustment is shown in figure 8.
• When the volume up button is pressed, the upper picture scanning decreases and the
lower picture scanning increases.
• When the volume down button is pressed, the upper picture scanning increases and the
lower picture scanning decreases.
• Press the stand-by button on the remote control to store.
Vertical Angle
Adjust the Vertical Angle so that the picture is centred.
The effect of this adjustment is shown in figure 9.
•  When the volume up button is pressed, side pincushion changes, specially the lower
picture.
• When the volume down button is pressed, side pincushion changes, specially the lower
picture.
• Press the stand-by button on the remote control to store.
Vertical Bow
Adjust the Vertical Amplitude so that the picture is centred.
The effect of this adjustment is shown in figure 10.
•  When the volume up button is pressed, side pincushion changes from pincushion to
barrel shape, specially the lower picture.
• When the volume down button is pressed, side pincushion changes from pincushion to
barrel shape, specially the lower picture.
• Press the stand-by button on the remote control to store.
Vertical Amplitude
Adjust the Vertical Amplitude so that the picture is over-scanned.
The effect of this adjustment is shown in figure 9.
• When the volume up button is pressed, the vertical size of the picture increases.
Fig.8
Fig.9
Fig.10
Fig.11
Fig.7
Page of 44
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Sharp 28HW-53 (serv.man9) Service Manual ▷ Download

  • DOWNLOAD Sharp 28HW-53 (serv.man9) Service Manual ↓ Size: 4.65 MB | Pages: 44 in PDF or view online for FREE
  • Here you can View online or download the Service Manual for the Sharp 28HW-53 (serv.man9) in PDF for free, which will help you to disassemble, recover, fix and repair Sharp 28HW-53 (serv.man9) CTR. Information contained in Sharp 28HW-53 (serv.man9) 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.