DOWNLOAD Sony KV-28CS70B Service Manual ↓ Size: 45.39 MB | Pages: 76 in PDF or view online for FREE

Model
KV-28CS70B
Pages
76
Size
45.39 MB
Type
PDF
Document
Service Manual
Brand
Device
TV
File
kv-28cs70b.pdf
Date

Sony KV-28CS70B Service Manual ▷ View online

- 13 -
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SECTION 2 DISASSEMBLY
2-1. Rear Cover Removal
To remove lift the main bracket rear slightly and slide the
chassis away from the beznet. Ensure that the interconnecting
leads are released from their purse locks to prevent damage
being caused.
When refitting the chassis ensure that the main bracket is
located in the beznet guide slots before sliding the chassis
forwards. Refit the inter-connecting leads in their respective
purse locks.
2-3. Chassis Removal and Refitting
2-2. Service Position
Remove the rear cover fixing screws indicated and pull the
rear cover backwards away from the set.
Position the chassis as indicated to access the solder side of
the PWB’s. To gain access to the underside of the boards
follow the instructions on page 16. [Removal and Replacement
of the main bracket bottom plates].
Note: Before removing the rear cover completely,
disconnect the speaker connector which is located on
the inside of the set.
- 14 -
To remove the G Board release the clips circled and remove
the screw from the middle of the board, then ease the
board gently away from the support bracket.
Removal of the D board follows the same procedure.
Clips
If the M Board needs to be removed for testing when the
chassis is placed in its service position, it would be necessary
to use an extender board and extension cable as indicated
above.
The Extender board and extension cable are available as a
service part by ordering the part number as indicated.
2-6. Service Connector for M Board
To A
Board
From M
Board
Extender Board Assembly A-1642-293-A
2-7. Wire Dressing
Ensure that wires do not touch heatsinks and high temperature
hotspots. All wires must be kept at a minimum distance of
20mm away from the EHT lead
20mm
20mm
To remove the M Board gently release the two clips with a
screwdriver and remove the board from its socket vertically.
2-4. G Board Removal
2-5. M Board Removal
- 15 -
How to handle the Anode-Cap
1.
To prevent damaging the surface of the anode-cap do not use
sharp materials.
2.
Do not apply too great a pressure on the rubber, as this may cause
damage to the anode connector.
3.
A metal fitting called a shatter hook terminal is fitted inside the
rubber cap.
4.
Do not turn the rubber foot over excessively, this may cause
damage if the shatter hook sticks out.
Removal of the Anode-Cap
2-
8
. Picture Tube Removal
WARNING:
BEFORE REMOVING
THE ANODE CAP
High voltage remains in the CRT even
after the power is disconnected. To
avoid electric shock, discharge CRT
before attempting to remove the anode
cap. Short between anode and CRT
coated earth ground strap.
Coated Earth
Ground Strap
  1. Discharge the anode of the CRT and remove the anode cap.
  2. Unplug all interconnecting leads from the Deflection yoke, neck
assy, degaussing coils and CRT grounding strap.
  3. Remove the C Board from the CRT.
  4. Remove the chassis assembly.
  5. Loosen the Neck assembly fixing screw and remove.
  6. Loosen the Deflection yoke fixing screw and remove.
  7. Place the set with the CRT face down on a cushion and remove
the Degaussing Coil holders.
  8. Remove the Degaussing Coils.
  9. Remove the CRT grounding strap and spring tensioners.
 10. Unscrew the four CRT fixing screws [ located on each CRT
corner ] and remove the CRT.
[Take care not to handle the CRT by the neck.]
Anode button
a
REMOVAL  PROCEDURE.
Turn up one side of the rubber cap in
the direction indicated by the arrow  a
1
2    Using a thumb pull up the rubber cap
      firmly in the direction indicated by the
      arrow  b
3    When one side of the rubber cap is
      separated from the anode button, the
      anode-cap can be removed by turning
      up the rubber cap and pulling it up in
      the direction of the arrow   c
b
b
c
2
4
6
8
10
5
 9
3
7
1
- 16 -
For safety reasons, on no account should the plates be removed
and not refitted after servicing.
REMOVAL AND REPLACEMENT OF THE MAIN
-
BRACKET
BOTTOM PLATES.
(1)  REMOVING THE PLATES
In the event of servicing being required to the solder side of the printed wiring boards, the
bottom plates fitted to the main chassis bracket require to be removed. This is performed by
cutting the gates with a sharp wire cutter at the locations indicated by the arrows.
Note : There are 2 plates fitted to the main bracket. Only remove the necessary plate to gain
access to the printed wiring board.
(2)  REFITTING THE PLATES
Because the plates differ in size it is important that the correct plates are refitted in their original
location.
Please note that the plates need to be rotated 180 degrees from their cut position to allow the
tabs to be fitted into their catch positions.
Tab
Catch
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