Sharp PZ-50HV2U Service Manual page 76

PZ-50HV2, PZ-50HV2E
PZ-50HV2U
AUDIO SECTION
Measurement condition
Video Input Signal : FULL FIELD COLOR-BAR
Audio Input Signal : 1kHz Sine Carve 0.2Vrms
Volume : 60 (MAX)
AV Selection : STANDARD
SRS : OFF
FOCUS : OFF
AUDIO AMP ASSY
CN5001 - pin 4 (L) GND
1
V: 0.1V/div. H: 0.2msec/div.
IC5202 - pin 14 (LOUT) GND
2
V: 0.1V/div. H: 0.2msec/div.
IC5201 - pin 19 (FOCUSOUTL)
3
V: 0.1V/div. H: 0.2msec/div.
Caution in the measurement
Audio Power Amp. (IC5002: LA4628) on the AUDIO AMP Assy is BTL system, and,
as for the power amplifier and the speaker output,
ground. Therefore be careful not to connect the measuring instrument as the following
figures. (Power amplifier may be damaged.)
IC5002 - pin 1 (IN1) GND
4
V: 0.1V/div. H: 0.2msec/div.
4.4V
J5003 - pin 5 (L+) GND
5
V: 1V/div. H: 0.2msec/div.
5.8V
GND J5003 - pin 6 (L–) GND
6
V: 1V/div. H: 0.2msec/div.
5.9V
Oscilloscope
CH1 CH2
GND and the speaker output (- side) becomes
a short state on the oscilloscope.
1
etc.
7
Measurement
Point
AUDIO AMP SP TERMINAL
ASSY
Wrong connection example
J5003 - pin 5 (L+) pin 6 (L–)
7
V: 2V/div. H: 0.2msec/div.
1.6V
7.3V
7.3V
8 0
poles becomes hot for the
10
Speaker
ASSY
SP TERMINAL ASSY
CN5301 - pin 1 (L+) GND
8
V: 1V/div. H: 0.2msec/div.
0V
CN5301 - pin 2 (L–) GND
9
V: 1V/div. H: 0.2msec/div.
CN5301 - pin 1 (L+) pin 2 (L–)
10
V: 2V/div. H: 0.2msec/div.
7.3V
7.3V
0V