Table of Contents
Advertisement
5.0 p e r fo r m a n c e t e s t s
5.2
Performance test procedure
For test point
(TP)
references, see section 6.0 Test Points.
No
Action
5.2.15.
Right channel
check
operation of
protection
circuit
5.2.16.
Left channel
check mute
operation
5.2.17.
Left channel
check mute
operation
reverse polarity
5.2.18.
Right channel
check mute
operation
Test Equipment
Audio Analyser
output voltage: 100
mV
Output frequency: 1
kHz
Oscilloscope
ch1:
0.5 V/div
0.2 ms/div
ch2:
0.2 V/div
0.2 ms/div
trigger: ch1
Multimeter set to
diode test
Multimeter set to
diode test
Multimeter set to
diode test
Details
Turn VOLUME knob to minimum.
Leave probe on cathode of D943 (TP11).
Short circuit loudspeaker terminal.
Slowly increase VOLUME. Check
oscilloscope traces with Figure 5.2.
Trace will appear briefly and will
disappear when amplifier mutes.
Disconnect input signal and loudspeaker
leads.
Turn VOLUME knob to 12 o'clock.
Connect negative probe to 0 V
Connect positive probe to input socket
signal pin
(TP
21).
Make sure amplifier mutes.
Disconnect positive probe.
Make sure mute relay resets (not muted).
Relay will click.
Connect positive probe to 0 V
Connect negative probe to input socket
signal pin
(TP
21).
Make sure amplifier mutes.
Disconnect positive probe.
Make sure mute relay resets (not muted).
Relay will click.
Connect negative probe to 0 V
Connect positive probe to input socket
signal pin
(TP
22).
Make sure amplifier mutes.
Disconnect positive probe.
Make sure mute relay resets (not muted).
Relay will click.
(TP
0).
(TP
0).
(TP
0).
14
Hide quick links:
Advertisement
Table of Contents
