Safety Related Adjustments; D Board; Hv Regulation Circuit Check And Adjustment; D Board 3-1. Hv Regulation Circuit Check And Adjustment - Sony KP-57WV600 Service Manual

D BOARD

3-1. HV REGULATION CIRCUIT CHECK
AND ADJUSTMENT
When replacing the following components marked with a Y on the
schematic diagram always check the HV regulation, and if necessary
re-adjust.
Part Replaced (
)
A BOARD:
HV Block, T8005 (FBT),
T8004 (LOT), R8129,
D8038, R8128, C8129,
R8223, R8102, R8230,
R8055, R8153, C8083,
R8139, C8079, D8051,
D8013, R8140, D8043,
R8163, C8090, D8015.
R8142, R8131, Q8021,
IC8006, D Board
OPERATION CHECK
1. Receive the all white signal.
2. Set PIC MAX/BRT CENT.
3. ConÞ rm that the voltage between CN8015 1 PIN and GND is less
than 7.80VDC.
HV REGULATION ADJUSTMENT
1. Connect a HV static voltmeter to the unconnected plug of the
high-voltage block.
2. Power on the set.
3. Repeat steps 1 and 2 as above.
4. ConÞ rm that the static voltmeter reading is 31.0 ± 0.4V.
5. If not, adjust with VR8001 to the speciÞ ed value.
6. After adjustment, put the VR cover on VR8001 (as shown below) and
apply sufÞ cient amount of epoxy resin around VR8001.
SECTION 3: SAFETY-RELATED ADJUSTMENTS
Adjustment (  )
HV REGULATOR
VR8001
Remove the cap from
the unused terminal and
connect a static voltmeter
there.
epoxy resin
VR8001
3-2. HV HOLD DOWN CIRCUIT OPERATION
CHECK AND ADJUSTMENT
When replacing the following components marked with a Y on the
schematic diagram always check the hold-down voltage and re-adjust
when necessary.
Part Replaced (
A BOARD:
HV Block, T8005 (FBT),
T8004 (LOT), C8123,
C8124, Q8043, Q8035,
C8104, R8171, D8036,
R8043, R8035, C8088,
C8086, R8159, D8022,
C8054, R8166, C8100,
IC8008, D8019, D8020,
R8201, C8118, D8028,
R8196, FB8001, D Board
OPERATION CHECK
1. Receive the dot signal.
2. Set PIC MIN/BRT MIN.
3. ConÞ rm that the voltage between cathode of D8038 (JW171) and
GND is more than 23.0V DC.
4. Using an external DC Power supply, apply the voltage shown below
between cathode of D8038 (JW171) on "D" and GND, then conÞ rm
that the HV-Prot circuit works. (Raster disappears)
Apply DC voltage: Less than 29.05V DC.
HV HOLD-DOWN ADJUSTMENT
1. Connect a HV static voltmeter to the unconnected plug of the
high-voltage block.
2. Power on the set.
3. Connect an external 10kΩ VR at CN8015 and adjust this VR so that
the high voltage is 34.50kV.
4. Adjust VR8002 to the point that the HV-Prot circuit works (Raster
disappears) at 34.50 ± 0.50kV reading on the static voltmeter.
5. After adjustment, put the VR cover on VR8002 and apply sufÞ cient
amount of epoxy resin around VR8002 as the same manner for
VR8001.
— 56 —
KP-57WV600/57WV700/

) Adjustment (
HV HOLD DOWN
VR8002
65WV600/65WV700
 )