Installation And Service Instructions; Circuit Protection; X-Radiation Protector Circuit Test; High Voltage Check - Sharp 21G-FX10L Service Manual

CHAPTER 3.
E Market 21G-FX10L Service Manual 21G-FX10L TV

INSTALLATION AND SERVICE INSTRUCTIONS

INSTALLATION AND SERVICE INSTRUCTIONS
Note: (1) When performing any adjustments to resistor controls and transformers use non-metallic
screwdrivers or TV alignment tools.
(2) Before performing adjustments, the TV set must be on at least 15 minutes.

CIRCUIT PROTECTION

The receiver is protected by a 3.15A fuse (F701),
mounted on PWB-A, wired into one side of the AC
line input.

X-RADIATION PROTECTOR CIRCUIT TEST

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 110~220V 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. Receive a good local channel.
4. Connect a digital voltmeter to C602 +ve and make
sure that the voltmeter reads 20 ±1.1V.
5. Apply external 28.5V DC at C602 +ve 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 C602 -ve and C602 +ve.
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.

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 110~220V
AC line voltage, with a strong air signal or a properly
tuned in test signal.
3. Enter the service mode and set Y-mute ON by using
Service R/C.
4. The voltage should be approximately 26kV (at zero
beam).
If a correct reading cannot be obtained, check circuitry
for malfunctioning components. After the voltage test,
make Y-mute off to the normal mode.
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21G-FX10L