Horizontal Oscillator Disable Circuit - Panasonic CT-30WX54J Service Manual

Connect the test equipment to the proper ground(hot) or (cold) when servicing, or incorrect voltages
will be measured.
WARNING
This receiver has been designed to meet or exceed applicable safety and x-ray radiation protection as
specified by government agencies and independent testing laboratories.
To maintain original product safety design standards relative to x-ray radiation and shock and fire
hazard, parts indicated with the symbol on the schematic must be replaced with identical parts. Order
parts from the manufacturers partscenter using the parts numbers shown in this service manual, or
provide the chassis number and the part reference number.
For optimum performance and reliability, all other parts should be replaced with components of
identical specification.

HORIZONTAL OSCILLATOR DISABLE CIRCUIT

This chassis employs a special circuit to protect against excessive high voltage and beam current. If,
for any reason, the high voltage and beam current exceed a predetermined level this protective circuit
activates and detunes the horizontal oscillatorthat limits the high voltage. The over-voltage protection
circuit is not adjustable. However, if components indicated by the symbol on the schematic in either
the horizontal sweep system or the over-voltage protection circuit itself are changed, theoperation of
the circuit should be checked using the following procedure:
Equipment needed to check the disabled circuit:
1. High voltage meter (0 ~ 50kV)
2. Variac or isolation transformer
3. D.C. current meter
4. Digital voltmeter
PREPARATION
1. Connect receiver to A.C. 120 Volts. Do not turn ON.
2. Connect HIGH VOLTAGE meter to 2nd anode (H.V. button).
NOTE
Use cold ground for negative lead.