— 10 —
A-700T
b) HV Hold-Down Check
1) Using an external DC Power supply, apply the
voltage shown below between cathode of D511
on "D" Board and GND, and confirm that the
HV Hold-Down circuit works. (Raster disappears)
Standard voltage: 35.00 + 0.05 VDC
Check Condition
• Input voltage
: 120 + 2 VAC
• Input signal
: Any pattern (fH = 64 kHz)
• Controls
: CONT
2
Maximum
: BRT
2
Center
c) Beam Protector Check
1) Using an external DC power supply, apply the
voltage 7.00 + 0.05 VDC between pin 11 of FBT
(T501) and GND, and confirm that the voltage
of both ends C519 is with in the voltage range
shown below.
Standard voltage: Less than 3.26 VDC
Check Condition
• Input voltage
: 120 + 2 VAC
• Input signal
: Any pattern (fH = 64 kHz)
• Controls
: CONT
2
Maximum
: BRT
2
Center
d) +B MAX. Check
1) Input white cross hatch (fH = 64 kHz) signal.
2) Set CONT and BRT to Maximum
3) Input voltage: 120 + 2 VAC
Note
: Use NF power supply or make sure that
distortion factor is 3% or less.
4) Confirm that the voltage is within the voltage
range shown below.
Standard voltage: 151.0 + 4.25 VDC
Measurement Point: CN505 Pin 1 and GND
SECTION 3
SAFETY RELATED ADJUSTMENT
Part Replaced (
[
)
RV501
Part Replaced (
]
)
D - BOARD
IC801, IC901, IC904, FBT T501, D511, D515, D596,
R532, R533, R534, R535, R538, R539, R540, R541,
R542, R543, R544, R545, R807, R822, R823, R824,
R939, R996, RV501, C509, C515, C516, C517, C519,
C528, C531, C542, C548, C549, C802, C814, C815,
C904, C910, R598, R599
When replacing parts shown in the table below, the
following operational checks must be performed as a
safety precaution against X-rays emissions from the unit.
Allow the unit to warm up for one minute prior to
checking the following conditions:
a
) HV Regulator Check
1) Input white cross hatch signal. (fH = 64 kHz)
2) Set H.Size data to minimum.
3) Cut off Screen VR (G2).
4) Input voltage: 120 + 2 VAC
5) Confirm that the voltage is within the voltage range
shown below:
Standard voltage: 25.0KV + 0.2KV
6) When replacing components identified by
]
, make
sure to recheck the High Voltage.
7) Verify the High Voltage as shown above (25.0KV + 0.2KV)
is within specification. If not, set H. SIZE data at
minimum (-127) and then adjust RV501 on "D" Board.
8) After adjusting the High Voltage within specification,
put the RV cover on RV501 as shown below and apply
sufficient amount of RTV around RV501.
10
4
R V 5 0 1