- 9 -
27J-S100/180/260
CJ27S10/26
CIRCUIT PROTECTION
The receiver is protected by a 4.0A fuse
(F701), mounted on PWB-A, wired into
one side of the AC line input.
X-RADIATION PROTECTOR CIRCUIT
TEST
HIGH VOLTAGE CHECK
High voltage is not adjustable but must be checked
to verify that the receiver is operating within safe
and efficient design limitations as specified checks
should be as follows:
1. Connect an accurate high voltage meter between
ground and anode of picture tube.
2. Operate receiver for at least 15 minutes at 120V AC
line voltage, with strong air signal or properly tuned
in test signal.
3. Set service mode on, service No.19 and Bus data
"01" (Y-mute on ).
4. The voltage should be approximately 28.3kV(27J-
S100/S120,CJ27S10/26),29.3kV(27J-S180) (at
zero beam).
If a correct reading cannot be obtained, check
circuitry for malfunctioning components. After the
voltage test, make Y-mute off (normal mode).
INSTALLATION AND SERVICE INSTRUCTIONS
Note: (1) When performing any adjustments to resistor controls and transformers use non-metallic
screwdriver or TV alignment tools.
(2) Before performing adjustment, TV set must be on at least 15 minutes.
After service has been performed on the horizontal
deflection system, high voltage system, B+ system,
test the X-Radiation protection circuit to ascertain
proper operation as follows:
1) Apply 120V AC using a variac transformer for
accurate input voltage.
2) Allow for warm up and adjust all customer controls
for normal picture and sound.
3) Select a local channel.
4) Connect a digital voltmeter to TP653 and make sure
that the voltmeter reads 11.4V.
5) Apply external 13.8V DC at TP653 by using an
external DC supply, TV must be shut off.
6) To reset the protector, unplug the ac cord and make
a short circuit between TP651 and TP652.Now make
sure that normal picture appears on the screen.
7) If the operation of the horizontal oscillator does not
stop in step 5, the circuit must be repaired before the
set is returned to the customer.
To Next Page
Loading...
Need help?
General
