B (135 V) Voltage Check; High Voltage Regulator Check - Sony BVM-D14H1E Maintenance Manual

+B (135 V) Voltage Check

1. Connect a digital voltmeter across C645 on the G
board.
2. Turn on the main power.
3. Connect the 1080/60i 100 IRE signal (see note) to
input connector.
Note: 1125 (1080) 100 IRE signal
4. Push the BRIGHTNESS and CONTRAST buttons to
their MANUAL positions (to turn the green LEDs on
the buttons.)
5. Set the BRIGHTNESS and CONTRAST buttons to
their MAX positions.
6. Check that the following DC voltage appears.
135.0 ± 0.8 V
7. Turn off the main power.
8. Disconnect the digital voltmeter.

High Voltage Regulator Check

When the following parts (the parts to which the
is attached on the schematic diagram) are replaced, be sure
to perform the following checks.
G board ....... IC515, IC519, IC520, T502, R1509,
R1514, R1576, R1577, R592, R593,
R599
1. Turn off the main power.
2. Connect an electrostatic voltmeter to the anode cap of
CRT tube.
. . . . . Electrostatic voltmeter: It must have already been
calibrated to have the input impedance of 2 x 10
or more. Singer ESH-27X or ESH-23X or equiva-
lent
3. Turn on the main power.
4. Connect the 1080/60i monoscope signal (see note) to
input connector.
Note: 1125 (1080) monoscope signal
5. Push the BRIGHTNESS and CONTRAST buttons to
their MANUAL positions (to turn the green LEDs on
the buttons.)
6. Set the BRIGHTNESS and CONTRAST buttons to
their mechanical center positions.
7. Check that the following high voltage appears.
22.5 ± 1.0 kV
8. Turn off the main power.
9. Disconnect the electrostatic voltmeter.
4-2
[Connection]
G board (Side B)
1 2
A
B
C
D
E
F
G
H
I
D512
mark
J
R1522
K
Ω
9
3 4 5 6 7
C645
GND
200kΩ
IC523-Pin 2
BVM-D14H1U/D14H5U/D14H1E/D14H5E/D14H1A/D14H5A
Digital
voltmeter
Digital
voltmeter
Ammeter
20kΩ