– 25 –
GENERAL ADJUSTMENTS
SPECIFIC INFORMATIONS
CIRCUIT CHECKS
HIGH VOLTAGE CHECK
CAUTION: Checking should be done following the steps be-
low.
1. Connect an accurate high voltage meter. (See ANODE
VOLTAGE MEASURING METHOD)
2. Turn on the receiver. Set the BRIGHTNESS and CON-
TRAST to minimum (zero beam current).
3. High voltage must be measured below (B) kV.
Refer to table-1 for high voltage (B).
(See SETTING & ADJUSTING DATA on page 26)
4. Vary the BRIGHTNESS to both extremes to be sure the
high voltage does not exceed the limit under any condi-
tions.
CAUTION:
When the following parts fail, check the High Voltage after re-
placing.
FS CIRCUIT CHECK
The Fail Safe (FS) circuit check is indispensable for the final
check in servicing. Checking should be done following the
steps below.
1. Turn the receiver on.
2. Temporarily short TP-R-1 and TP-X-1 on the DEF Board
with a jumper wire.
Raster and sound will disappear.
3. The receiver must remain in this state even after removing
the jumper wire. This is the evidence that the FS circuit is
functioning properly.
4. To obtain a picture again, temporarily turn the receiver off
and allow the FS circuit more than 5 seconds to reset. Then
turn the receiver on to produce a normal picture.
Location
No.
Name
Remark
T461
Z450
C404
C407
C408
R465
R466
R467
Q437
Flyback Trans.
CR Block
Capacitor
Capacitor
Capacitor
Resistor
VR
Resistor
IC
TFB3083AD
TPA5007
1200pF,
±
3%
1200pF,
±
3%
1200pF,
±
3%
2.2k
Ω
±
1%
2k
Ω
B
5.6k
Ω
±
1%
TA75902p
Troubleshooting Guide for Fail Safe Circuit
(When Fail Safe Circuit Operate)
ANODE VOLTAGE MEASURING METHOD
CAUTION: Take extra precaution when measuring this high
voltage. High voltages are also present in surround-
ing circuit boards (CRT DRIVE assembly, DEFLEC-
TION assembly, and POWER SUPPLY assembly).
1. Disconnect the FBT anode cable as outlined below. Meas-
ure high voltage at the point where the cable enters the
FBT.
2. Holding the rubber cover firmly, turn it counterclockwise
and check that the lock has been disengaged. (See Fig. b
on page 9.)
3. Determine the extent of the rubber cover before discon-
necting the cable.
4. Pull straight up the anode cable to disconnect.
5. When reconnecting the cable, proceed in the reverse or-
der.
After reconnecting, tug on the cable to check that it is se-
cure.
Check that the set returns to normal operation when
the terminal "TP-X1" is grounded with jumper wire.
Check the voltage across
Capacitor C471 is
approximately (C) volts.
Refer to table –4 for
FBT detection voltage
(C) .
Power circuit or
horizontal circuit
or vertical circuit
is faulted.
Fail Safe circuit is faulted.
(See SETTING & ADJUSTING
DATA on page 26)
YES
NO
NO
YES
