JVC KS-AX4500 Service Manual page 7

Test method
1. Check the voltage and frequency of the secondary
toroidal coil.
FREQUENCY:22.87kHz ± 50Hz
.
VOLTAGE VALUE:60Vp-p ± 2.5V
2. Measure the secondary toroidal coil, if the standard
frequency value of 22.87 kHz ± 50 Hz is not attained,
measure the R60 terminal, then adjust the SV01 so
that the R60 terminal becomes 22.87 kHz ± 50Hz.
Note: When measuring, adjust and apply power
with no signal or load on each board.
DC/DC CONVERTER SECOND GENERATOR SWITCHING
TEST ITEM SPECIFICATION
VOLTAGE TEST 60Vp-p±2.5V
FREQUENCY CHECK 22.87KHz±50Hz
FREQUENCY COUNTER
TEST SET
CONDITION
OSCILLOSCOPE
VOLT/DIV: 10
TIME/DIV: 10mcec
MAIN PCB
(+)
(-)
R60
Q01
C01
C31
R03
MAIN PCB
KS-AX4500
POWER SUPPLY
14.4V
Measuring
Points
60Vp-p
±2.5V
1-7