Safety Related Adjustments; Hv Regulation Circuit Check And Adjustment; B Ovp Confirmation - Sony KP-53XBR300 Service Manual

KP-53XBR300/61XBR300
RM-Y902
[ D BOARD]
4-1. HV REGULATION CIRCUIT CHECK AND
ADJUSTMENT
When replacing the following components marked with
the schematic diagram always check HV regulation, and if nec-
essary re-adjust.
: R8194, R8202
: C8064, C8066, C8070, C8074, C8076,C8082
D8042
IC8002, IC8007, IC8008
Q8022
R8093, R8095, R8096, R8105, R8108
R8112, R8113, R8114, R8115, R8126
R8128, R8136, R8138, R8139, R8154
R8157, R8168, R8173, R8174, R8177
R8178, R8195, R8196, R8201
T8002 (LOT), T8003 (FBT)
HV BLOCK, D BOARD
OPERATION CHECK
1. Connect a HV static voltmeter to the unconnected plug of
the high-voltage block.
2. Connect a 33kΩ variable resistor, set to maximum value,
across CN8008.
3. Power on the set.
4. Receive dot signal pattern.
5. Gradually lower the value of the variable resistor and check
that the hold-down circuit operates at a static voltmeter read-
ing of 31.0 ± 0.5kV dc when the raster disappears.
HV HOLD-DOWN ADJUSTMENT
1. REPART STEPS 1 ~ 5 as above.
2. Just at the point hold-down circuit begins to operate switch
off the set.
3. Remove the VR connected across CN8008, and measure it's
resistance.
4. Solder a resistor value, nearest to the measured value, across
CN8008.
5. Reconfirm operation check.
RM-Y902

SAFETY RELATED ADJUSTMENTS

Remove the cap off from
the unused terminal and
connect a static voltmeter
there.
Fig. 4-1
SECTION 4
4-2. HV HOLD DOWN CIRCUIT OPERATION
CHECK AND ADJUSTMENT
on When replacing the following components marked with
the schematic diagram always check hold-down voltage and if
necessary re-adjust.
: R8196, R8201
: D8026, D8032, D8035, D8050
IC8006, IC8009, IC8010
Q8021, Q8031
R8092, R8094, R8097, R8109, R8110,R8117,
R8118, R8121, R8123, R8125, R8129, R8135,
R8140, R8155, R8190, R8191, R8192, R8193,
R8194, R8198, R8202
T8002 (LOT), T8003(FBT)
HV BLOCK, D BOARD
OPERATION CHECK
1. Connect a HV static voltmeter to the unconnected plug of
the high-voltage block.
2. Power on the set.
3. Receive dot signal patterm.
4. Check that the HV static voltmeter is readind 34.0 ± 0.5V dc.
HV Regulation ADJUSTMENT
1. Repart step 1 as above.
2. Connect 33kΩ variable resistor, set to maximum value, to
CN8008.
3. Power on the set.
4. Receive dot signal pattern.
5. Gradually lower the value of the variable resistor until the
static voltmeter is reading 34.0 ± 0.5 kVdc.
6. Switch off the swt.
7. Remove the VR connected across CN8008, and measure its
value.
8. Solder a resistor value, nearest to the measured value, across
CN8008.
9. Reconfirm operation check.

4-3. +B OVP CONFIRMATION

1. Connect a voltmeter to TP. OVP and ground.
2. Supply 120VAC to variable autotransformer.
3. Power on the Set.
4. Supply 150VDC to TP. OVP.
5. Check the OVP operate.
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on