CIRCUIT CHECKS
HIGH VOLTAGE CHECKFS CIRCUIT CHECK
CAUTION: There is no HIGH VOLTAGE ADJUSTMENT onThe Fail Safe (FS) circuit check is indispensable for the final
this chassis. Checking should be done fchecollok in serwingvicing. Checking should be done following the
the steps below.steps below.
1. Connect an accurate high voltage meter to the anode of1. Turn the receiver on.
the picture tube.2. Temporarily short TP- (R) and TP- (X) on the DEF/POWER
2. Turn on the receiver. Set the BRIGHTNESS and CON-Board with a jumper wire.
TRAST to minimum (zero beam current).Raster and sound will disappear.
3. High voltage must be measured below (B) kV.3. The receiver must remain in this state even after removing
the jumper wire. This is the evidence that the FS circuit is
Refer to table-1 for high voltage (B).
functioning properly.
(See SETTING & ADJUSTING DATA on page 23)
4. To obtain a picture again, temporarily turn the receiver off
4. Vary the BRIGHTNESS to both extremes to be sure the
GENERAL ADJUSTMENTSand allow the FS circuit more than 5 seconds to reset. Then
high voltage does not exceed the limit under any condi-
turn the receiver on to produce a normal picture.
tions.
CAUTION:Troubleshooting Guide for Fail Safe Circuit
When the following parts fail, check the High Voltage after
replacing.
Check that the set returns to normal operation when
pin 12 of Z801 is grounded with jumper wire.
Descriptions
Location
Name
No.40", 43"50"~65"
YESNO
T461FlybackTFB3088AD?
C407Capacitor 4300pF, ?3%5100pF, ?3%
Check the voltage acrossFaulty power
C408Capacitor 0.027mF, ?5%0.022mF, ?3%
Capacitor C419 iscircuit or hori-
C445Capacitor 0.015mF, ?5%0.022mF, ?5%
approximately (C) volts.zontal circuit.
C446Capacitor 0.011mF, ?5%0.012mF, ?5%
SPECIFIC INFORMATIONSC447Capacitor 6200PF, ?3%5600pF, ?3%Refer to table �4 for
fall safe voltage (C) .
C448Capacitor 8200PF, ?5%?
C449Capacitor 1000PF, ?3%?
YES
(See SETTING & ADJUSTING
DATA on page23)
ANODE VOLTAGE MEASURING METHOD
CAUTION: Take extra precaution when measuring this high
voltage. High voltages are also present in
NO
surrounding circuit boards (CRT DRIVE assem-
bly, DEFLECTION assembly, and POWERDefective Fail Safe Circuit
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 order.
After reconnecting, tug on the cable to checsecurek that i.t is
� 22 � |
ACEC
TOSHIBA
