Sony KPR-41EXR95, Service Manual

Page: 58 / 129

REGULATOR ADJUSTMENTS
1.
2.
3.
4 .
5.
6.
Connect the HV adjustment resistance jig to R
902 of the N board.
i
(Adjustment jig)
Remove the red anode lead wire foe the CRT
tube from the high-voltage block and connect the
static voltmeter instead.
Receive 120 VAC power voltage and monoscope
pattern signal. Set PICTURE and BRIGHTNESS
to the standard.
Turn on power. To adjust the resistance of R902
with the adjustment jig to read the rated value,
31.50
Receive all-white signal. Set BRIGHTNESS to the
standard. Maximize PICTURE. Confirm that the
rated value,
is read.
Cut off RGB by VP26, 27, 28 of the service
commander. Verify that the rated value,
is read.
VOLTAGE
1.
2.
Receive 130 1 VAC power voltage and
monoscope pattern signal. Set BRIGHTNESS to
standard and maximize PICTURE.
Connect a digital multimeter between the
line and the ground on the G board, and confirm
that the rated value,
is read.
CHECKING TEE OVP
(overvoltage protection)
CIRCUIT
1. Receive 120 VAC power voltage and monoscope
pattern signal. Maximize PICTURE and
BRIGHTNESS.
2. Remove R638 from the G board and connect a
variable resistor (4.7 to instead.
3. Turn the variable resistor of and confirm
that the OVP circuit is activated and luster
disappears when B+ voltage reads the rated value,
125.0
BEAM CURRENT PROTECTOR ADJUSTMENT
R852, R852)
1.
2.
3.
4.
5.
Receive 120 VAC power voltage and monoscope
pattern signal. Maximize BRIGHTNESS.
Connect the collector and the emitter of Q807
(on the N board)
Remove the jumper connector from the N-8
connector on the N board. Then connect an ABL
ammeter between pin and pin of the N-8
connector.
ABL ammeter
Raise PICTURE current gradually. Confirm that
the beam current protector circuit is activated
and luster disappears under the rated value, 3400
the collector and the emitter of
Verify that the protector circuit is activated and
luster disappears similarly.
AF
TER
RE
P
LACIN
G
1. When replacing check the B+ voltage.