Inf1 - Onkyo TX-SR502 Service Manual

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-3-3 "
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-3-3 " comes out.
T e s t - 3 - 0 3
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-3-3 "
Refer to the clause of " Output level detection ".
2. Connect the resistor 1.8kohms /1W between "HT2" and "COM" terminals of P6301.
P6301
1.8kohms
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 - 3-03
TH1
TH2
COM
TH1
COM
TH2
P6301
MEMORY
Test - 3-03
FM STEREO
U16
NAAF-8245
POWER AMPLIFIER PC BOARD
MEMORY
TX-SR502/E/8250/HT-R520
Front side