Onkyo TX-SR402 Service Manual page 49

OPERATION CHECK-3
OUTPUT LEVEL & THERMAL DETECTION
<Check procedure by test mode>
The following is the procedure of checking detection operation of a microprocessor in false, by using test mode.
Output level detection
1. Set the unit to test mode " Test-3-2 "
1-1. Press and the hold down the CD button , then press the STANDBY/ON button when the unit is Power ON.
T e s t - _
1-2. Press the VIDEO2 button, while the display of " Test - _ " has come out.
Unit will be in the state of "Test-3-00".
T e s t - 3 - 0 0
1-3. Repeat and press SPEAKERS B until the display of " Test-3-2 " comes out.
T e s t - 3 - 0 2
2. Apply signal (sine wave 1kHz, -1.5dBV) to MULTI CHANNEL (FL, FR, SL, SR, C) terminal, each channel.
3. Check that FM STEREO indicator is display come out.
6. Press the STANDBY/ON button, and exit from test mode.
Thermal detection
1. Set the unit to test mode " Test-3-2 "
Refer to the clause of "OUTPUT LEVEL DETECTION".
2. Connect the resistor 2.7kohms /1W between "HT1" and "COM" terminals of P6301.
2.7kohms
1W
3. Check that FM STEREO indicator is display come out.
6. Press the STANDBY/ON button, and exit from test mode.
FM STEREO
Test - 3-02
TH1
P6301
P6301 TH1
COM
COM
FM STEREO
Test - 3-02
FM STEREO
Front side
U17
NAAF-7875
POWER AMPLIFIER PC BOARD
FM STEREO
TX-SR402/8240/HT-R420